[doc]: Update (or remove) project coding standards wiki

[sirugh]

Describe the request
The coding standards wiki was supposed to be a living document but hasn't been updated in some time, likely around when we started adding graphql. But as you can see, even the gql docs are dated as we now recommend passing an operations object instead of queries and `mutations.

We should remove outdated information, update existing, and add new where missing.

Possible solutions

• Do it all in one go, or at least remove outdated/inaccurate information first.
• Because the wiki is editable in browser on github, and not maintained in code, I recommend using a gist to propose updates and have the gist reviewed before applying changes.

Screenshots
If applicable, add screenshots to help explain the problem.

Please let us know whether this is a new topic or a topic change request:

• New Topic Request (ie. missing entire topic/section)
• Topic Change Request (ie. spelling, organization)

[m2-assistant]

Hi @sirugh. Thank you for your report.
To help us process this issue please make sure that you provided sufficient information.

Please, add a comment to assign the issue: @magento I am working on this

---

• Join Magento Community Engineering Slack and ask your questions in #github channel.

[sirugh]

@magento export issue to JIRA project PWA as Task

[github-jira-sync-bot]

✅ Jira issue https://jira.corp.magento.com/browse/PWA-1786 is successfully created for this GitHub issue.