CCI-2 Add github issue template for github addons

.github/issue_template.md

@@ -0,0 +1,22 @@
+<!-- 
+Please use https://www.cuba-platform.com/discuss for discussion, support, and reporting problems about GrapesJs-addon.
+This repository is only for issues of the GrapesJs-addon.
+
+When creating an issue, provide as much as possible of the following information: 
+-->
+
+### Environment
+
+- Platform version: X.Y.Z <!-- e.g. 6.8.7 -->
+- Addon version: X.Y.Z <!-- e.g. 1.2.3 -->
+<!-- Optional. Remove irrelevant lines. -->
+- Client type: <!-- Web, Polymer, Portal, Desktop -->
+- Browser: <!-- Chrome, etc. -->
+- Database: <!-- PostgreSQL, etc. -->
+- Operating system: <!-- Windows, Linux, macOS -->
+
+### Description of the bug or enhancement
+
+- Minimal reproducible example
+- Expected behavior
+- Actual behavior