Add some install* / uninstall* scripts

Scripts/uninstall-opera-browser.ps1

@@ -0,0 +1,25 @@
+<#
+.SYNOPSIS
+	Uninstalls Opera Browser
+.DESCRIPTION
+	This PowerShell script uninstalls Opera Browser from the local computer.
+.EXAMPLE
+	PS> ./uninstall-opera-browser
+.LINK
+	https://github.com/fleschutz/PowerShell
+.NOTES
+	Author: Markus Fleschutz | License: CC0
+#>
+
+try {
+	"Uninstalling Opera Browser, please wait..."
+
+	& winget uninstall "Opera Browser"
+	if ($lastExitCode -ne "0") { throw "Can't uninstall Opera Browser, is it installed?" }
+
+	"Opera Browser is uninstalled now."
+	exit 0 # success
+} catch {
+	"Sorry: $($Error[0])"
+	exit 1
+}