doc: tor.md updates

Summary:
core#20757:

doc: update -proxy, -onion and -onlynet info in tor.md

Improve the description of what these options do with regards to
tor or network traffic.

doc: update/improve automatic tor section of tor.md

doc: update tor.md manual config, move after automatic config

core#20587:

[doc] Tidy up Tor doc (more stringent)

This is a backport of core#20757 [2/2] (all the tor.md changes from that PR) and core#20587

Depends on D11031

Test Plan: proofreading

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Subscribers: Fabien

Differential Revision: https://reviews.bitcoinabc.org/D11032