Add Plausible analytics (#1749)

Author: StanFromIreland

_templates/page.html

@@ -0,0 +1,8 @@
+{% extends "!page.html" %}
+
+{% block extrahead %}
+{{ super() }}
+{% if not READTHEDOCS %}
+<script defer data-domain="devguide.python.org" src="https://analytics.python.org/js/script.outbound-links.js"></script>
+{% endif %}
+{% endblock %}

conf.py

@@ -1,4 +1,5 @@
 import json
+import os
 from urllib.request import urlopen
 
 extensions = [
@@ -37,6 +38,7 @@
     "source_repository": "https://github.com/python/devguide",
     "source_branch": "main",
 }
+templates_path = ['_templates']
 html_static_path = ['_static']
 html_css_files = [
     'devguide_overrides.css',
@@ -50,6 +52,10 @@
 # Set to '' to prevent appending "documentation" to the site title
 html_title = ""
 
+html_context = {
+    "READTHEDOCS": bool(os.getenv("READTHEDOCS")),
+}
+
 linkcheck_allowed_redirects = {
     # Edit page
     r"https://docs.google.com/document/d/.*/": r"https://docs.google.com/document/d/.*/edit",  # noqa: E501