Mem-Doc Improvements

[mrsharm]

Improvement 1: Fixed Menu Indentation Issues

The menu indentation is important as it forms a workflow to diagnose GC related performance issues in itself. Fixing these will help with readability. Fixed in the Chinese version of the doc, as well.  

Fix 1: GC Fundamentals

Before:

After:

Fix 2: High % Pause Time in GC and Large GC Heap Size

Before:

After: