Clean up `sg` README, add VISION.md document, make quickstart quick, link to tickets, ... (!25435) · Merge requests · Administrator / sourcegraph

Administrator requested to merge mrn/update-sg-readme into main Sep 28, 2021

Created by: mrnugget

This does a lot of things, most importantly, though: it removes outdated information and makes the README.md easier to digest for newcomers.

I converted most of the TODOs/ideas in there into tickets: sg tickets

Clean up `sg` README, add VISION.md document, make quickstart quick, link to tickets, ...