Added issue template

ISSUE_TEMPLATE.md

@@ -0,0 +1,26 @@
+# Feature request
+
+* Did you check if there wasn't a similar feature request?
+* Did you read [this FAQ](https://github.com/M66B/open-source-email/blob/master/FAQ.md#FAQ15)?
+
+# Bug report
+
+* Did you check if there wasn't a similar bug report?
+* Are you using the [latest version](https://github.com/M66B/open-source-email/releases) of the app?
+
+## Expected behavior
+
+
+## Actual behavior
+
+
+## Steps to reproduce the problem
+
+1.
+1.
+1.
+
+## Version
+
+* App version:
+* Android version: