RFR: Section on project maintenance [v2]

[Lance Andersen]

On Wed, 21 Sep 2022 19:56:05 GMT, Jesper Wilhelmsson <jwilhelm at openjdk.org> wrote:

>> * New section on project maintenance
>> * New infographics on push/defer during rampdown
>> * Moved JDK Release Process section to follow the Release Note section
>> * Minor fixes
>
> Jesper Wilhelmsson has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Update src/guide/project-maintenance.md
>   
>   Co-authored-by: Ludvig Janiuk <ludvig.janiuk at gmail.com>

looks good

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Marked as reviewed by lancea (Author).

PR: https://git.openjdk.org/guide/pull/92