Fix table display

Add APIv4 architecture docs

Co-Authored-By: Mikey O'Toole <mikey@mjco.uk>

Done has been deprecated for some time. Then is functionally equivalent and is forward-compatible with api4.

Reorganze Api4 Usage

Updates requirements

Remove pass-by-reference from form variable

My understanding is it's meaningless for objects

Clarify how to setup automatic publishing

Contribution pre/post hooks

Explain when mailingID and messageTemplateID are passed through

Add "Populate Help Text on the Payment Processor Administrator Screen" section

Add better example for transaction handling

Fix extensions' code block

Add in documentation on setting and retrieving contact settings using…

Co-Authored-By: Tim Otten <totten@civicrm.org>

Update explorer url

Add in documentation on setting and retrieving contact settings using the Civi:: facade and also add in note about the deprecation of the ::setItem function

Fix indentation of code block in hook_civicrm_permission

Fixed typo

Incorporate Abandoned Extensions process

Typo fix & SetCheckPermissions example.