Refactor documentation source format + toolchain

[gggeek]

trafficstars

Since GitHub supports natively "nice" display AsciiDoc format, we might give it a go...

Steps: [x] convert current docbook to asciidoc as doc. source [x] alter manual building toolchain so that we go asciidoc => pdf, or asciidoc => docbook => pdf [ ] rewrite user manual to make it useful for version 4 API users, drop docs of version 3 API [ ] create GHA workflows which build the manual and api docs and upload them to the website [ ] ... [ ] profit!

This will most likely happen after the build toolchain has been ported to something other than make

[gggeek]

Mostly done - but docs have to be rewritten from scratch given the big API changes, and the whole process tested

[gggeek]

The user manual rewrite is a WIP.

Otoh the API docs are now generated using Sami, and for version 4.0.0 have been uploaded to http://gggeek.github.io/phpxmlrpc/doc-4/api/index.html

[gggeek]

Back from Sami to PhpDocumentor

[gggeek]

Moved from makefiles to taskfiles (plain shell scripts). Asciidoctor is now used for all conversions of the manual to target formats. The manual has been rewritten, and demo files reviewed