Rethink how rule citation and description work in style-linter

[snsokolov]

From the discussion #1455 (comment)

Currently every rule has a citation referring to the Google's Verilog Style Guide (which is not published yet) or some other "unknown" style guide, which is also not published.
So even if the citation is there, it may not be possible for a user (except for those who work at Google) to actually read it.

This is further complicated by the fact that Verilog Linter:

1. Has many rules which are not part of the Google's VSG and may never be
2. Some of rules are contradictory to Google's VSG or other rules, like this one so they will never be a part of the same style guide
3. There is also a PR to override rule descriptions Override style guide citations #817 which I guess is an attempt to make .desc look more like a Style Guide quote

I think we need to rethink how citation and description work in style-linter.

@hzeller