Add @pinarx to the CODEOWNERS for messaging update sandbox URL (#466)

Author: jshcrowthe

.github/CODEOWNERS

@@ -19,9 +19,9 @@ packages/storage  @sphippen
 packages/storage-types  @sphippen
 
 # Messaging Code
-packages/messaging  @gauntface
-packages/messaging-types  @gauntface
-integration/messaging  @gauntface
+packages/messaging  @gauntface @pinarx
+packages/messaging-types  @gauntface @pinarx
+integration/messaging  @gauntface @pinarx
 
 # Auth Code
 packages/auth  @bojeil-google @wti806 @tmsch

.github/ISSUE_TEMPLATE.md

@@ -32,8 +32,11 @@ Are you in the right place?
 -->
 #### Relevant Code:
 
-<!-- Fork this JSBin, provide your own URL, or a simple code snippet below -->
-http://jsbin.com/rinilu/edit?js,console
+<!-- 
+  Reproduce the issue on StackBlitz and provide your forked URL
+  or give us some sample code below
+-->
+https://stackblitz.com/fork/firebase-issue-sandbox
 
 ```javascript
 // TODO(you): code here to reproduce the problem