Add Pester build system

Add a Pester build system for PowerShell files which runs
Invoke-Pester at the current location.

Author: theaquamarine

Support/Pester.sublime-build

@@ -0,0 +1,9 @@
+{
+    "cmd": ["pwsh", "-NoProfile","-NonInteractive", "-ExecutionPolicy", "Bypass","-Command","Invoke-Pester"],
+    "selector": "source.powershell",
+    "file_regex": "at <ScriptBlock>, (.+): line ([0-9]+)$",
+
+    "windows": {
+        "cmd": ["powershell.exe", "-NoProfile","-NonInteractive", "-ExecutionPolicy", "Bypass","-Command","Invoke-Pester"],
+    }
+}