Use -LiteralPath consistently in Install-TukuiAddon; add PS 5.1 install instructions to README

- Switch Get-ChildItem and Copy-Item in extraction section to -LiteralPath
  for consistency with the function's path safety checks (review thread #13)
- Use -LiteralPath and -ErrorAction SilentlyContinue in finally cleanup
  to prevent masking original errors (review thread #14)
- Add Windows PowerShell 5.1 Install-Module alternative alongside
  Install-PSResource in README (review thread #15)

Author: MariusStorhaug

README.md

@@ -14,8 +14,13 @@ for [World of Warcraft](https://worldofwarcraft.blizzard.com/).
 To install the module from the PowerShell Gallery:
 
 ```powershell
+# PowerShell 7.4+ (Install-PSResource is built-in)
 Install-PSResource -Name ElvUI
 Import-Module -Name ElvUI
+
+# Windows PowerShell 5.1 (use Install-Module instead)
+Install-Module -Name ElvUI -Scope CurrentUser
+Import-Module -Name ElvUI
 ```
 
 ## Usage

src/functions/private/Install-TukuiAddon.ps1

@@ -64,17 +64,17 @@
         }
 
         # Copy new folders
-        $extractedFolders = Get-ChildItem -Path $extractPath -Directory -ErrorAction Stop
+        $extractedFolders = Get-ChildItem -LiteralPath $extractPath -Directory -ErrorAction Stop
         foreach ($folder in $extractedFolders) {
             $destination = Join-Path -Path $AddOnsPath -ChildPath $folder.Name
             Write-Verbose "  Installing $($folder.Name)"
-            Copy-Item -Path $folder.FullName -Destination $destination -Recurse -Force -ErrorAction Stop
+            Copy-Item -LiteralPath $folder.FullName -Destination $destination -Recurse -Force -ErrorAction Stop
         }
 
         Write-Verbose "$($Addon.Name) $($Addon.Version) installed successfully!"
     } finally {
-        if (Test-Path $tempDir) {
-            Remove-Item $tempDir -Recurse -Force
+        if (Test-Path -LiteralPath $tempDir) {
+            Remove-Item -LiteralPath $tempDir -Recurse -Force -ErrorAction SilentlyContinue
         }
     }
 }