Clarify "bug" in issue template (#6463)

* Clarify "bug" in issue template

* Update ISSUE_TEMPLATE.md

* Updating per JB, HH feedback

ISSUE_TEMPLATE.md

@@ -1,10 +1,12 @@
-For feature requests, please see: http://www.mattermost.org/feature-requests/.
+Per Mattermost guidelines, GitHub issues are for bug reports: http://www.mattermost.org/filing-issues/
-For troubleshooting questions, please post on the forums: http://forum.mattermost.org/.
 
-For issues with the product, please follow the steps at http://www.mattermost.org/filing-issues/ and post here in the following format:
+For troubleshooting see: http://forum.mattermost.org/.
+For feature proposals see: http://www.mattermost.org/feature-requests/
+
+If you've found a bug--something appears unintentional--please report using the following format: 
 
 #### Summary
-Issue in one concise sentence
+Bug report in one concise sentence
 
 #### Steps to reproduce
 How can we reproduce the issue (what version are you using?)
@@ -12,7 +14,7 @@ How can we reproduce the issue (what version are you using?)
 #### Expected behavior
 Describe your issue in detail
 
-#### Observed behavior
+#### Observed behavior (that appears unintentional) 
 What did you see happen? Please include relevant error messages and/or screenshots.
 
 #### Possible fixes