Add developer documentation for the Federation Sender and add a documentation mechanism using Sphinx. (#15265)

Co-authored-by: Patrick Cloke <clokep@users.noreply.github.com>

dev-docs/conf.py

@@ -0,0 +1,50 @@
+# Configuration file for the Sphinx documentation builder.
+#
+# For the full list of built-in configuration values, see the documentation:
+# https://www.sphinx-doc.org/en/master/usage/configuration.html
+
+# -- Project information -----------------------------------------------------
+# https://www.sphinx-doc.org/en/master/usage/configuration.html#project-information
+
+project = "Synapse development"
+copyright = "2023, The Matrix.org Foundation C.I.C."
+author = "The Synapse Maintainers and Community"
+
+# -- General configuration ---------------------------------------------------
+# https://www.sphinx-doc.org/en/master/usage/configuration.html#general-configuration
+
+extensions = [
+    "autodoc2",
+    "myst_parser",
+]
+
+templates_path = ["_templates"]
+exclude_patterns = ["_build", "Thumbs.db", ".DS_Store"]
+
+
+# -- Options for Autodoc2 ----------------------------------------------------
+
+autodoc2_docstring_parser_regexes = [
+    # this will render all docstrings as 'MyST' Markdown
+    (r".*", "myst"),
+]
+
+autodoc2_packages = [
+    {
+        "path": "../synapse",
+        # Don't render documentation for everything as a matter of course
+        "auto_mode": False,
+    },
+]
+
+
+# -- Options for MyST (Markdown) ---------------------------------------------
+
+# myst_heading_anchors = 2
+
+
+# -- Options for HTML output -------------------------------------------------
+# https://www.sphinx-doc.org/en/master/usage/configuration.html#options-for-html-output
+
+html_theme = "furo"
+html_static_path = ["_static"]