refactor: Add more checks to pre-commit

Updated existing pre-commit hooks and added some new hooks:

- Remove trailing whitespace
- Ensure every non-empty file ends with a new line
- Check YAML file validity
- Prevent adding large files
- Ensure any scripts with shebangs are executable

Added a GitHub action to run pre-commit on every commit. Removed any
existing actions which duplicate pre-commit.

Ran pre-commit on the codebase.

docs/src/templates/setup.ps1.mustache

@@ -74,7 +74,7 @@ if (Test-CommandExists Get-Acl) {
     $permission = (Get-Acl $pwd).Access |
     ?{$_.IdentityReference -match $env:UserName `
         -and $_.FileSystemRights -match "FullControl" `
-        -or $_.FileSystemRights -match "Write" } | 
+        -or $_.FileSystemRights -match "Write" } |
              Select IdentityReference,FileSystemRights
 
     If (-Not $permission){
@@ -141,7 +141,7 @@ if ($keyboard_type -eq "shield") {
         Write-Host "Wired split is not yet supported by ZMK."
         exit 1
     }
-    
+
     $shields = $keyboard_siblings
     $board = $($($boards.keys)[$choice])
     $boards = ( $board )

docs/src/templates/setup.sh.mustache

@@ -97,7 +97,7 @@ select opt in "${options[@]}" "Quit"; do
             keyboard_arch=${keyboards_arch[$keyboard_index]}
             keyboard_basedir=${keyboards_basedir[$keyboard_index]}
             keyboard_title=${options[$keyboard_index]}
-            keyboard_sibling_var=${keyboard}_siblings[@]                                                  
+            keyboard_sibling_var=${keyboard}_siblings[@]
             keyboard_sibling_first=${keyboard}_siblings[0]
             if [ -n "${!keyboard_sibling_first}" ]; then
                 keyboard_siblings=${!keyboard_sibling_var}