Update issue templates

Author: Doug Mahugh

.github/ISSUE_TEMPLATE/direct-issues-to-office-js.md

@@ -0,0 +1,12 @@
+---
+name: direct issues to office-js
+about: direct issues to office-js repo
+title: ''
+labels: ''
+assignees: ''
+
+---
+
+Thank you for building custom functions. If you have an issue running your custom function, please log an issue in the official office-js repo here: [https://github.com/OfficeDev/office-js/issues](https://github.com/OfficeDev/office-js/issues)
+
+If you have an issue related to the current Excel Custom Functions sample, then log that in this repo at [https://github.com/OfficeDev/Excel-Custom-Functions/issues](https://github.com/OfficeDev/Excel-Custom-Functions/issues)