feat(installer-pwsh): create boilerplate powershell install file

Install.ps1

@@ -0,0 +1,75 @@
+<#
+
+.SYNOPSIS
+Installer for Lepton
+
+.DESCRIPTION
+Installs Lepton onto selected Firefox profiles
+
+.INPUTS
+TODO: input directories for installation?
+Would need to discuss a non-interactive install system
+
+.OUTPUTS
+TODO: output directories that Lepton has been installed to?
+
+.PARAMETER u
+Specifies whether to update a current installation
+Defaults to false
+
+.PARAMETER f
+Specifies a custom path to look for Firefox profiles in
+
+.PARAMETER p
+Specifies a custom name to use when creating a profile
+
+.PARAMETER h
+Shows this help message
+
+.PARAMETER ?
+Shows this help message
+
+.PARAMETER WhatIf
+Runs the installer without actioning any file copies/moves
+Equivelant to a dry-run
+
+.EXAMPLE
+PS> .\Install.ps1 -u -f C:\Users\someone\ff-profiles
+Updates current installations in the profile directory 'C:\Users\someone\ff-profiles'
+
+.LINK
+https://github.com/black7375/Firefox-UI-Fix#readme
+
+#>
+
+[CmdletBinding(
+    SupportsShouldProcess = $true,
+    PositionalBinding = $false
+)]
+
+param(
+    [Alias("u")]
+    [Switch]$Update=$false,
+    [Alias("f")]
+    [string]$ProfilePath,
+    [Alias("p")]
+    [string]$ProfileName,
+    [Alias("h")]
+    [Switch]$Help=$false
+)
+
+function Install-Lepton {
+    # TODO: implement
+}
+
+function Check-Help {
+    # Cheap and dirty way of getting the same output as '-?' for '-h' and '-Help'
+    if ($Help) {
+        Get-Help "$PSCommandPath"
+        exit 0
+    }
+}
+
+Check-Help
+Install-Lepton
+