Add issue template

Closes signalapp#5257
// FREEBIE

Changes template as per comments

.github/ISSUE_TEMPLATE.md

@@ -0,0 +1,33 @@
+<!--
+Please note this is a bug tracker, not a support forum. If you need support, please use
+http://support.whispersystems.org/
+or email [email protected]
+
+Delete any sections that aren't relevant.
+-->
+
+<!-- mark with x between the [ ] -->
+I have:
+- [ ] searched open and closed issues for duplicates
+- [ ] read https://github.com/WhisperSystems/Signal-Android/wiki/Submitting-useful-bug-reports
+
+### Bug description
+
+### Steps to reproduce
+- add your steps here
+- as a list
+- using hyphens
+
+### Screenshots
+<!-- Drag and drop images here, or post a link -->
+
+### Device info
+<!-- Replace examples with your info -->
+ **Model:** Manufacturer Model XVI
+
+ **Android version:** 0.0.0
+
+ **Signal version:** 0.0.0
+
+### Link to debug log
+