v20.3.0
doc/start: add vstart install guide
doc/start/ceph.conf: trim the sample ceph.conf file
doc: s/Whereas,/Although/
doc: Update Slack invite links
doc: Fixes a typo in controllers section of hardware recommendations
doc/start: Mention RGW in Intro to Ceph
doc/start: update os-recommendations.rst
doc: remove references to ceph-deploy