This pull request adds a custom `docmd` plugin to improve how
documentation links to source files are handled, ensuring that
repo-root-relative links work both when editing locally and on the
published site. The main changes include introducing the new plugin,
updating configuration to use it, and documenting its behavior.
**Plugin integration and configuration:**
* Added a new local plugin `github-source-links` in `docmd-plugins/`,
which rewrites repo-root-relative links (e.g., `/src/.../Foo.cpp`) in
Markdown files to absolute GitHub blob URLs during the documentation
build process, ensuring links remain functional on the published site.
[[1]](diffhunk://#diff-c2c746e6974a6cfdd229031c2977f2bb0dca37c6d5f598ed45dc0d9f0b74c7caR1-R52)
[[2]](diffhunk://#diff-a97f3ce59c97313aacd716b9874b445d162c45ee2e6ef9fd2db59fe17235e1cfR1-R8)
* Updated `docmd.config.json` to register the new plugin under the
`plugins` key, enabling it for documentation builds.
* Updated `package.json` to include the plugin as a dependency,
referencing the local plugin directory.
**Documentation updates:**
* Updated `README.md` to document the new `docmd-plugins/` folder,
explain the purpose of repo-root-relative links, and describe how the
plugin rewrites these links for the published site.
This pull request introduces a new, automated workflow for building and
publishing the developer documentation website using
[docmd](https://docmd.io/). The static site is now generated from
`doc/devdocs`, built in the `doc/devdocs-website` folder, and deployed
to GitHub Pages via a GitHub Actions workflow. The build output is not
committed to the repository but is instead published as an artifact.
Supporting configuration files, documentation, and `.gitignore` entries
are also added to streamline local development and CI/CD.
**Automated build and deployment:**
* Added `.github/workflows/regenerate-devdocs-website.yml` to build the
static site with docmd and deploy it to GitHub Pages automatically on
changes to `doc/devdocs` or `doc/devdocs-website`, or via manual
trigger.
**Project setup and configuration:**
* Added `doc/devdocs-website/package.json` to define the Node.js
project, pin the docmd version, and provide scripts for local
development and builds.
* Added `doc/devdocs-website/docmd.config.json` to configure docmd (site
title, source, output directory, base path).
* Added `doc/devdocs-website/.npmrc` to disable lockfile generation,
ensuring fresh dependency installs each build.
**Documentation and housekeeping:**
* Added `doc/devdocs-website/README.md` with instructions for editing,
building, and publishing the docs website.
* Added `doc/devdocs-website/.gitignore` to exclude the generated
`site/` output from version control.
