Docs feedback: /docs/sources/logql/_index.md

The issue with this top level doc page is it gets super sciency with "literals", "scalars", "vectors" , order of operations, vector matching, etc.

Needs to be abit more novice friendly for the most common reader so as not to scare them off. And then have advanced topics as sub topics for the power users.

Focus on basic log search commands and then provide some basic examples such as:

basic search commands to get you started

• {label=value} |= error
• {label=value} | logfmt | field=value