[Docs] Adding information about general triaging

R=machenbach@chromium.org
NOPRESUBMIT=true
NOTRY=true

Review URL: https://codereview.chromium.org/1375533003

Cr-Commit-Position: refs/heads/master@{#30999}

docs/triaging_issues.md

-# Instructions on how to assign V8 issues in the Chromium tracker
+# How to get an issue triaged 
+* *V8 tracker*: Set the state to `Untriaged`
+* *Chromium tracker*: Set the state to `Untriaged` and add the label `Cr-Blink-JavaScript`
 
-Please assign any issues to the V8 specialty sheriffs of one of the
+# How to assign V8 issues in the Chromium tracker
+Please assign issues to the V8 specialty sheriffs of one of the
 following categories:
 
   * Stability: jkummerow@c....org, adamk@c....org