feat(CI): add the GitHub Super Linter

The GitHub Super Linter is a more robust and better supported
tool than the current GitHub Actions we are using.

Running these checks:

ERROR_ON_MISSING_EXEC_BIT: true
VALIDATE_BASH: true
VALIDATE_BASH_EXEC: true
VALIDATE_EDITORCONFIG: true
VALIDATE_MARKDOWN: true
VALIDATE_SHELL_SHFMT: true
VALIDATE_YAML: true

https://github.com/marketplace/actions/super-linter
https://github.com/github/super-linter

Added the GitHub Super Linter badge to the README.

Also updated the pre-commit framework and added
more documentation on pre-commit.

Added one more pre-commit check: check-executables-have-shebangs

Added one extra check for merge conflicts to our
GitHub Actions.

EditorConfig and Markdown linting.

Minor grammar and spelling fixes.

Update linter.yml

4 files changed, 57 insertions, 57 deletions

diff --git a/build_config/ArduinoDue.rb b/build_config/ArduinoDue.rb
index 9292183e2..9baf1ef92 100644
--- a/build_config/ArduinoDue.rb
+++ b/build_config/ArduinoDue.rb
@@ -11,7 +11,7 @@ MRuby::CrossBuild.new("ArduinoDue") do |conf|
   # ARDUINO_PATH = '/Applications/Arduino.app/Contents/Java'
   # GNU Linux
   ARDUINO_PATH = '/opt/arduino'
-   # Arduino IDE <= 1.5.6
+  # Arduino IDE <= 1.5.6
   BIN_PATH = "#{ARDUINO_PATH}/hardware/tools/g++_arm_none_eabi/bin"
   # Arduino IDE >= 1.5.7
   # BIN_PATH = "#{ARDUINO_PATH}/hardware/tools/gcc-arm-none-eabi-4.8.3-2014q1/bin"
diff --git a/build_config/IntelEdison.rb b/build_config/IntelEdison.rb
index a33d83bd7..65b6a9a5f 100644
--- a/build_config/IntelEdison.rb
+++ b/build_config/IntelEdison.rb
@@ -21,7 +21,7 @@ MRuby::CrossBuild.new('core2-32-poky-linux') do |conf|
   #
   POKY_EDISON_PATH = '/opt/poky-edison/1.7.2'
 
-  POKY_EDISON_SYSROOT =  "#{POKY_EDISON_PATH}/sysroots/core2-32-poky-linux"
+  POKY_EDISON_SYSROOT  = "#{POKY_EDISON_PATH}/sysroots/core2-32-poky-linux"
   POKY_EDISON_X86_PATH = "#{POKY_EDISON_PATH}/sysroots/i386-pokysdk-darwin"
   POKY_EDISON_BIN_PATH = "#{POKY_EDISON_X86_PATH}/usr/bin/i586-poky-linux"
 
diff --git a/build_config/host-shared.rb b/build_config/host-shared.rb
index 6b19b3640..38cab8145 100644
--- a/build_config/host-shared.rb
+++ b/build_config/host-shared.rb
@@ -23,7 +23,7 @@ MRuby::Build.new do |conf|
 
   # file extensions
   conf.exts do |exts|
-     exts.library = '.so'
+    exts.library = '.so'
   end
 
   # file separator
diff --git a/build_config/nintendo_switch.rb b/build_config/nintendo_switch.rb
index 02c067fea..549c1f269 100644
--- a/build_config/nintendo_switch.rb
+++ b/build_config/nintendo_switch.rb
@@ -1,73 +1,73 @@
 # Cross Compiling configuration for the Nintendo Switch, it requires Nintendo SDK
 # Tested on windows
 MRuby::CrossBuild.new('nintendo_switch_32bit') do |conf|
-		conf.toolchain :clang
-		NINTENDO_SDK_PATH = ENV['NINTENDO_SDK_ROOT']
+  conf.toolchain :clang
+  NINTENDO_SDK_PATH = ENV['NINTENDO_SDK_ROOT']
 
-		include_paths = [
-			"#{NINTENDO_SDK_PATH}/Include",
-			"#{NINTENDO_SDK_PATH}/Common/Configs/Targets/NX-NXFP2-a32/Include"
-		]
+  include_paths = [
+    "#{NINTENDO_SDK_PATH}/Include",
+    "#{NINTENDO_SDK_PATH}/Common/Configs/Targets/NX-NXFP2-a32/Include"
+  ]
 
-		conf.cc do |cc|
-			cc.command = "#{NINTENDO_SDK_PATH}/Compilers/NX/bin/nx-clang++"
-			cc.include_paths += include_paths
-			cc.flags += ['-fpic -fno-short-enums -ffunction-sections -fdata-sections -fno-common -fno-strict-aliasing -fomit-frame-pointer -fno-vectorize -funsigned-char -O2 -g -mno-implicit-float']
-			cc.defines += 'NN_SDK_BUILD_RELEASE'
-		end
+  conf.cc do |cc|
+    cc.command = "#{NINTENDO_SDK_PATH}/Compilers/NX/bin/nx-clang++"
+    cc.include_paths += include_paths
+    cc.flags += ['-fpic -fno-short-enums -ffunction-sections -fdata-sections -fno-common -fno-strict-aliasing -fomit-frame-pointer -fno-vectorize -funsigned-char -O2 -g -mno-implicit-float']
+    cc.defines += 'NN_SDK_BUILD_RELEASE'
+  end
 
-		conf.cxx do |cxx|
-			cxx.command = "#{NINTENDO_SDK_PATH}/Compilers/NX/bin/nx-clang++"
-			cxx.include_paths += include_paths
-			cxx.flags += ['-fpic -fno-short-enums -ffunction-sections -fdata-sections -fno-common -fno-strict-aliasing -fomit-frame-pointer -fno-vectorize -funsigned-char -O2 -g -mno-implicit-float']
-			cxx.defines += 'NN_SDK_BUILD_RELEASE'
-		end
+  conf.cxx do |cxx|
+    cxx.command = "#{NINTENDO_SDK_PATH}/Compilers/NX/bin/nx-clang++"
+    cxx.include_paths += include_paths
+    cxx.flags += ['-fpic -fno-short-enums -ffunction-sections -fdata-sections -fno-common -fno-strict-aliasing -fomit-frame-pointer -fno-vectorize -funsigned-char -O2 -g -mno-implicit-float']
+    cxx.defines += 'NN_SDK_BUILD_RELEASE'
+  end
 
-		conf.archiver do |archiver|
-			archiver.command = "#{NINTENDO_SDK_PATH}/Compilers/NX/nx/armv7l/bin/llvm-ar"
-		end
+  conf.archiver do |archiver|
+    archiver.command = "#{NINTENDO_SDK_PATH}/Compilers/NX/nx/armv7l/bin/llvm-ar"
+  end
 
-		conf.linker do |linker|
-			linker.command = "#{NINTENDO_SDK_PATH}/Compilers/NX/nx/armv7l/bin/clang++"
-			linker.libraries = []
-		end
+  conf.linker do |linker|
+    linker.command = "#{NINTENDO_SDK_PATH}/Compilers/NX/nx/armv7l/bin/clang++"
+    linker.libraries = []
+  end
 
-		# Add your mrbgems
+  # Add your mrbgems
 end
 
 MRuby::CrossBuild.new('nintendo_switch_64bit') do |conf|
-		conf.toolchain :clang
-		NINTENDO_SDK_PATH = ENV['NINTENDO_SDK_ROOT']
+  conf.toolchain :clang
+  NINTENDO_SDK_PATH = ENV['NINTENDO_SDK_ROOT']
 
-		include_paths = [
-			"#{NINTENDO_SDK_PATH}/Include",
-			"#{NINTENDO_SDK_PATH}/Common/Configs/Targets/NX-NXFP2-a64/Include"
-		]
+  include_paths = [
+    "#{NINTENDO_SDK_PATH}/Include",
+    "#{NINTENDO_SDK_PATH}/Common/Configs/Targets/NX-NXFP2-a64/Include"
+  ]
 
-		conf.cc do |cc|
-			cc.command = "#{NINTENDO_SDK_PATH}/Compilers/NX/bin/nx-clang++"
-			cc.include_paths += include_paths
-			cc.flags += ['-fpic -fno-short-enums -ffunction-sections -fdata-sections -fno-common -fno-strict-aliasing -fomit-frame-pointer -fno-vectorize -funsigned-char -O2 -g -mno-implicit-float']
-			cc.flags << '--target=aarch64-nintendo-nx-elf'
-			cc.defines += 'NN_SDK_BUILD_RELEASE'
-		end
+  conf.cc do |cc|
+    cc.command = "#{NINTENDO_SDK_PATH}/Compilers/NX/bin/nx-clang++"
+    cc.include_paths += include_paths
+    cc.flags += ['-fpic -fno-short-enums -ffunction-sections -fdata-sections -fno-common -fno-strict-aliasing -fomit-frame-pointer -fno-vectorize -funsigned-char -O2 -g -mno-implicit-float']
+    cc.flags << '--target=aarch64-nintendo-nx-elf'
+    cc.defines += 'NN_SDK_BUILD_RELEASE'
+  end
 
-		conf.cxx do |cxx|
-			cxx.command = "#{NINTENDO_SDK_PATH}/Compilers/NX/bin/nx-clang++"
-			cxx.include_paths += include_paths
-			cxx.flags += ['-fpic -fno-short-enums -ffunction-sections -fdata-sections -fno-common -fno-strict-aliasing -fomit-frame-pointer -fno-vectorize -funsigned-char -O2 -g -mno-implicit-float']
-			cxx.flags << '--target=aarch64-nintendo-nx-elf'
-			cxx.defines += 'NN_SDK_BUILD_RELEASE'
-		end
+  conf.cxx do |cxx|
+    cxx.command = "#{NINTENDO_SDK_PATH}/Compilers/NX/bin/nx-clang++"
+    cxx.include_paths += include_paths
+    cxx.flags += ['-fpic -fno-short-enums -ffunction-sections -fdata-sections -fno-common -fno-strict-aliasing -fomit-frame-pointer -fno-vectorize -funsigned-char -O2 -g -mno-implicit-float']
+    cxx.flags << '--target=aarch64-nintendo-nx-elf'
+    cxx.defines += 'NN_SDK_BUILD_RELEASE'
+  end
 
-		conf.archiver do |archiver|
-			archiver.command = "#{NINTENDO_SDK_PATH}/Compilers/NX/nx/aarch64/bin/llvm-ar"
-		end
+  conf.archiver do |archiver|
+    archiver.command = "#{NINTENDO_SDK_PATH}/Compilers/NX/nx/aarch64/bin/llvm-ar"
+  end
 
-		conf.linker do |linker|
-			linker.command = "#{NINTENDO_SDK_PATH}/Compilers/NX/nx/aarch64/bin/clang++"
-			linker.libraries = []
-		end
+  conf.linker do |linker|
+    linker.command = "#{NINTENDO_SDK_PATH}/Compilers/NX/nx/aarch64/bin/clang++"
+    linker.libraries = []
+  end
 
-		# Add your mrbgems
+  # Add your mrbgems
 end