Add some install* / uninstall* scripts

Scripts/install-git-extensions.ps1

@@ -0,0 +1,25 @@
+<#
+.SYNOPSIS
+	Installs Git Extensions
+.DESCRIPTION
+	This PowerShell script installs Git Extensions.
+.EXAMPLE
+	PS> ./install-git-extensions
+.LINK
+	https://github.com/fleschutz/PowerShell
+.NOTES
+	Author: Markus Fleschutz | License: CC0
+#>
+
+try {
+	"Installing Git Extensions, please wait..."
+
+	& winget install --id GitExtensionsTeam.GitExtensions --accept-package-agreements --accept-source-agreements
+	if ($lastExitCode -ne "0") { throw "'winget install' failed" }
+
+	"Git Extensions installed successfully."
+	exit 0 # success
+} catch {
+	"Sorry: $($Error[0])"
+	exit 1
+}