PowerShell ISE path detection fallback

ICSharpCode.Decompiler.PowerShell/Demo.ps1

@@ -1,5 +1,13 @@
-Import-Module .\bin\Debug\netstandard2.0\ICSharpCode.Decompiler.Powershell.dll
-$decompiler = Get-Decompiler .\bin\Debug\netstandard2.0\ICSharpCode.Decompiler.Powershell.dll
+$basePath = $PSScriptRoot
+if ([string]::IsNullOrEmpty($basePath))
+{
+    $basePath = Split-Path -parent $psISE.CurrentFile.Fullpath
+}
+
+$modulePath = $basePath + '\bin\Debug\netstandard2.0\ICSharpCode.Decompiler.Powershell.dll'
+
+Import-Module $modulePath
+$decompiler = Get-Decompiler $modulePath
 
 $classes = Get-DecompiledTypes $decompiler -Types class
 $classes.Count