RFR: 8312882: Update the CONTRIBUTING.md with pointers to lifecycle of a PR [v3]

[Jesse Glick]

> @jaikiran in https://github.com/openjdk/jdk/pull/12871#issuecomment-1612310113 pointed me to a resource I had not previously found. https://openjdk.org/contribute is fine at a high level but still says things like
> 
>> When your change is ready, send a message to the appropriate development list…
> 
> which clearly predates Skara, and does not apparently link to anything more current. Whereas this https://github.com/openjdk/jdk/blob/master/doc/building.md is thorough and discoverable, finding accurate guidelines for proposing pull requests was tough.

Jesse Glick has updated the pull request incrementally with two additional commits since the last revision:

 - Hand-picked HTML diff since `make update-build-docs` rewrote everything https://github.com/openjdk/jdk/pull/14716#discussion_r1288412572
 - Keep it simple https://github.com/openjdk/jdk/pull/14716#discussion_r1288391918

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/14716/files
  - new: https://git.openjdk.org/jdk/pull/14716/files/649736c6..aa729ff8

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=14716&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=14716&range=01-02

  Stats: 15 lines in 2 files changed: 0 ins; 13 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/14716.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/14716/head:pull/14716

PR: https://git.openjdk.org/jdk/pull/14716