Add custom RST roles extlinks to the docs setup (aio-libs#6045)

This patch declares the following roles within Sphinx:
* issue
* pr
* commit
* gh
* user

They all correspond to respective GitHub URLs. For example,
the following will link a GitHub user page:

    :user:`webknjaz`

CHANGES/6045.misc

@@ -0,0 +1,2 @@
+Added `commit`, `gh`, `issue`, `pr` and `user`
+RST roles in Sphinx — :user:`webknjaz`.

docs/conf.py

@@ -43,8 +43,11 @@
 # extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
 # ones.
 extensions = [
- "sphinx.ext.viewcode",
+ # stdlib-party extensions:
+ "sphinx.ext.extlinks",
  "sphinx.ext.intersphinx",
+ "sphinx.ext.viewcode",
+ # Third-party extensions:
  "sphinxcontrib.asyncio",
  "sphinxcontrib.blockdiag",
 ]
@@ -81,9 +84,17 @@
 # The master toctree document.
 master_doc = "index"
 
-# General information about the project.
-project = "aiohttp"
-copyright = "2013-2020, aiohttp maintainers"
+# -- Project information -----------------------------------------------------
+
+github_url = "https:"
+github_repo_org = "aio-libs"
+github_repo_name = "aiohttp"
+github_repo_slug = f"{github_repo_org}/{github_repo_name}"
+github_repo_url = f"{github_url}/{github_repo_slug}"
+github_sponsors_url = f"{github_url}/sponsors"
+
+project = github_repo_name
+copyright = f"2013-2020, {project} maintainers"
 
 # The version info for the project you're documenting, acts as replacement for
 # |version| and |release|, also used in various other places throughout the
@@ -136,6 +147,17 @@
 # keep_warnings = False
 
 
+# -- Extension configuration -------------------------------------------------
+
+# -- Options for extlinks extension ---------------------------------------
+extlinks = {
+ "issue": (f"{github_repo_url}/issues/%s", "#"),
+ "pr": (f"{github_repo_url}/pull/%s", "PR #"),
+ "commit": (f"{github_repo_url}/commit/%s", ""),
+ "gh": (f"{github_url}/%s", "GitHub: "),
+ "user": (f"{github_sponsors_url}/%s", "@"),
+}
+
 # -- Options for HTML output ----------------------------------------------
 
 # The theme to use for HTML and HTML Help pages. See the documentation for
@@ -148,39 +170,39 @@
 html_theme_options = {
  "description": "Async HTTP client/server for asyncio and Python",
  "canonical_url": "http://docs.aiohttp.org/en/stable/",
- "github_user": "aio-libs",
- "github_repo": "aiohttp",
+ "github_user": github_repo_org,
+ "github_repo": github_repo_name,
  "github_button": True,
  "github_type": "star",
  "github_banner": True,
  "badges": [
  {
- "image": "https:/aio-libs/aiohttp/workflows/CI/badge.svg",
- "target": "https:/aio-libs/aiohttp/actions?query=workflow%3ACI",
+ "image": f"{github_repo_url}/workflows/CI/badge.svg",
+ "target": f"{github_repo_url}/actions?query=workflow%3ACI",
  "height": "20",
  "alt": "Azure Pipelines CI status",
  },
  {
- "image": "https://codecov.io/github/aio-libs/aiohttp/coverage.svg?branch=master",
- "target": "https://codecov.io/github/aio-libs/aiohttp",
+ "image": f"https://codecov.io/github/{github_repo_slug}/coverage.svg?branch=master",
+ "target": f"https://codecov.io/github/{github_repo_slug}",
  "height": "20",
  "alt": "Code coverage status",
  },
  {
- "image": "https://badge.fury.io/py/aiohttp.svg",
- "target": "https://badge.fury.io/py/aiohttp",
+ "image": f"https://badge.fury.io/py/{project}.svg",
+ "target": f"https://badge.fury.io/py/{project}",
  "height": "20",
  "alt": "Latest PyPI package version",
  },
  {
- "image": "https://img.shields.io/discourse/status?server=https%3A%2F%2Faio-libs.discourse.group",
- "target": "https://aio-libs.discourse.group",
+ "image": f"https://img.shields.io/discourse/status?server=https%3A%2F%2F{github_repo_org}.discourse.group",
+ "target": f"https://{github_repo_org}.discourse.group",
  "height": "20",
  "alt": "Discourse status",
  },
  {
  "image": "https://badges.gitter.im/Join%20Chat.svg",
- "target": "https://gitter.im/aio-libs/Lobby",
+ "target": f"https://gitter.im/{github_repo_org}/Lobby",
  "height": "20",
  "alt": "Chat on Gitter",
  },
@@ -268,7 +290,7 @@
 # html_file_suffix = None
 
 # Output file base name for HTML help builder.
-htmlhelp_basename = "aiohttpdoc"
+htmlhelp_basename = f"{project}doc"
 
 
 # -- Options for LaTeX output ---------------------------------------------
@@ -286,7 +308,13 @@
 # (source start file, target name, title,
 # author, documentclass [howto, manual, or own class]).
 latex_documents = [
- ("index", "aiohttp.tex", "aiohttp Documentation", "aiohttp contributors", "manual"),
+ (
+ "index",
+ f"{project}.tex",
+ f"{project} Documentation",
+ f"{project} contributors",
+ "manual",
+ ),
 ]
 
 # The name of an image file (relative to this directory) to place at the top of
@@ -314,7 +342,7 @@
 
 # One entry per manual page. List of tuples
 # (source start file, name, description, authors, manual section).
-man_pages = [("index", "aiohttp", "aiohttp Documentation", ["aiohttp"], 1)]
+man_pages = [("index", project, f"{project} Documentation", [project], 1)]
 
 # If true, show URL addresses after external links.
 # man_show_urls = False
@@ -328,10 +356,10 @@
 texinfo_documents = [
  (
  "index",
- "aiohttp",
- "aiohttp Documentation",
+ project,
+ f"{project} Documentation",
  "Aiohttp contributors",
- "aiohttp",
+ project,
  "One line description of project.",
  "Miscellaneous",
  ),