[FTS UI] Good to add some 'what is this' or 'help' for advanced Query options.

Given FTS is a very new feature and it is non-intuitive to decipher some of the advanced settings for the query

Attached screenshot

Example: Consistency Level -> A user might think of this similar to stale ok/false ( similar to views, n1ql): unsupported consistencyLevel: ok 

Enter numbers, which is also not the right way to do this.

Good to either

1. Provide a drop down or so pre-populated list of permissible entries
2. Provide additional help for understanding ( click here for help or 'whats this') on these settings to better assist the user on using these settings.