[powershell mode] Add extensions ps1, psd1 and psm1 to mode/meta.js

Author: Dominator008

mode/meta.js

@@ -102,7 +102,7 @@
     {name: "Pig", mime: "text/x-pig", mode: "pig", ext: ["pig"]},
     {name: "Plain Text", mime: "text/plain", mode: "null", ext: ["txt", "text", "conf", "def", "list", "log"]},
     {name: "PLSQL", mime: "text/x-plsql", mode: "sql", ext: ["pls"]},
-    {name: "PowerShell", mime: "application/x-powershell", mode: "powershell"},
+    {name: "PowerShell", mime: "application/x-powershell", mode: "powershell", ext: ["ps1", "psd1", "psm1"]},
     {name: "Properties files", mime: "text/x-properties", mode: "properties", ext: ["properties", "ini", "in"], alias: ["ini", "properties"]},
     {name: "ProtoBuf", mime: "text/x-protobuf", mode: "protobuf", ext: ["proto"]},
     {name: "Python", mime: "text/x-python", mode: "python", ext: ["py", "pyw"]},