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

Document BuildKit EoL Policy

provided best practice advice on report extension creation

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

pull recent changes from upstream master

This table is not relevant for several install methods (Vagrant/Docker/Generic).

For Ubuntu/Debian, I think it's useful information, but it's a bit
overwhelming, and what we're basically doing is elaborating on a couple
words (*it needs to be a __recent__, supported version of Ubuntu/Debian -
which is specifically yadda yadda...*).

If one is oblivious to this content and runs the install script on an
unsupported version of Ubuntu/Debian, that should be safe -- since the first
thing it does is to verify compatibility.

Note: not trying to bury - the next commit will call this out a bit more.

Flesh out information about financial items

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

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

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

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

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

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

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

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

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

This makes the new section match the other sections.

Nest "Create the default payment processor file" section under "Setup"

It seems to me like  "Create the default payment processor file" should be the first subheading under "Setup"

Improve APIv4 usage docs

This contains a mix of typo and style fixes, removes some bits that
were copied from APIv3 and adds some missing sections.

Mention the change in behaviour around check permissions in APiv4 in …

Start writing about financial entities