Add dev build tool for PHP manual across different manuals

[jordikroon]

I have been long thinking where this tool fits most. But given the docs from doc.php.net live here, all and everything depends on doc-base this feels most natural.

Currently it's very vague for new contributors how to contribute to the docs.

• It either requires either docker or manual cloning of multiple repositories which
• It requires make, which some developers may have never heard of
• Translations have their own set up building tools
• With the upcoming doc-extensions repository it adds even more complexity
• No way to include a linter

This PR adds a dev.php script that is primarily meant for local development. And should provide an all-in-one experience for everyone.

Basically:

php dev.php pull # Fetch changes
# Write docs ... 
php dev.php render xhtml # Build docs
php dev.php cs lint # Run linter
php dev.php cs fix # Run fixer (if linter fails)
php dev.php serve # Test changes
# Commit changes

For a language this would require the --lang= parameter

php dev.php pull --lang=it # Fetch changes
# Write docs ... 
php dev.php render xhtml --lang=it # Build docs
php dev.php cs lint --lang=it # Run linter
php dev.php cs fix --lang=it  # Run fixer (if linter fails)
php dev.php serve --lang=it  # Test changes
# Commit changes

Planning to introduce this tool in 3 stages (when this is considered ready):

• Stage 1: Through this PR. Use this tool, leave any feedback, share bugs, finetune
• Stage 2: Merge this PR, leave an official deprecation marker for the old tool, and update doc.php.net to encourage the use of the new tool
  Stage 3: Remove the old tool, in favor of the new tool

---

./dev.php

Dev build tool for the PHP manual, for every language, with or without
Docker. Missing sibling repositories (en, the translation, and without
Docker also phd/docbook-cs) are cloned automatically on first use.
With Docker, phd and docbook-cs ship inside the image and follow their
upstream heads automatically; a checkout next to doc-base overrides
the image's copy and is only moved by pull.

Usage:
  php dev.php <command> [options] [extra arguments]

Commands:
  pull          Clone missing sibling repositories and update existing ones
  configure     Assemble and validate the manual, without rendering
  render xhtml  configure + render the chunked XHTML manual to <lang>/output
  render php    configure + render the web (PHP) version to <lang>/output
  cs lint       Run docbook-cs; extra arguments are passed through (paths, --wide)
  cs fix        Same as cs lint, with --fix: rewrite violations that have fixers
  serve         Serve <lang>/output over HTTP
  docker build  Build the Docker image
  docker shell  Interactive shell inside the container

Options:
  --lang=XX    Language to operate on (default: en)
  --port=NNNN  Port for serve (default: 8080)
  --docker     Force Docker mode (default: used when available)
  --no-docker  Force local mode
  --yes, -y    Clone missing repositories without asking for confirmation

Any other argument after the command is passed through: to configure.php
for configure/render (e.g. --enable-xml-details), and to
docbook-cs for cs lint/cs fix (e.g. reference/datetime --wide).