Fix docs generation by upgrading Sphinx.

Add sponsor to dev docs and readme.

Makefile

@@ -258,8 +258,9 @@ test:
 
 .PHONY: docsdev
 docsdev: ./bin/activate requirements.txt
-	./bin/pip install --upgrade pip==21.3.1
-	./bin/pip install -r requirements.txt
+	./bin/python -m ensurepip --upgrade
+	./bin/python -m pip install --upgrade setuptools
+	./bin/pip3 install -r requirements.txt
 
 .PHONY: html
 html: doc

README.md

@@ -166,6 +166,11 @@ We accept donations via [Patreon](https://www.patreon.com/jcbrand) and [Liberapa
 
 ## Sponsors
 
+<p>
+  <a href="https://www.dotcom-monitor.com/sponsoring-open-source-projects/?utm_source=conversejs" target="_blank" rel="noopener">
+    <img alt="Dotcom-Monitor" src="https://raw.githubusercontent.com/conversejs/media/logos/dotcom-monitor.svg" width="200">
+  </a>
+</p>
 <p>
   <a href="https://bairesdev.com/sponsoring-open-source-projects/?utm_source=conversejs" target="_blank" rel="noopener">
     <img alt="BairesDev" src="https://raw.githubusercontent.com/conversejs/media/main/logos/bairesdev-primary.png" width="200">

docs/source/_templates/sponsors.html

@@ -2,6 +2,10 @@
 <h4 class="sidebar-title">Sponsored by</h4>
 </span>
 <ul class="sponsors-list">
+    <li><a href="https://www.dotcom-monitor.com/sponsoring-open-source-projects/?utm_source=conversejs" target="_blank" rel="noopener">
+            <img style="width: 10em" src="/media/logos/dotcom-monitor.svg" alt="Dotcom-Monitor">
+        </a>
+    </li>
     <li><a href="https://bairesdev.com/sponsoring-open-source-projects/?utm_source=conversejs" target="_blank" rel="noopener">
             <img style="width: 10em" src="/media/logos/bairesdev-primary.png" alt="BairesDev">
         </a>

index.html

@@ -249,7 +249,9 @@ <h2>Converse is supported by:</h2>
 
                     <p class="sponsors-text">Converse is a software commons, available at no cost to you or anyone else.
                        Sponsorships allow us to fund further development and improvements.
-                       If you'd like to sponsor this project, please visit <a href="https://www.patreon.com/jcbrand" target="_blank" rel="noopener">Patreon</a>,
+                       If you'd like to sponsor this project, please visit
+                       <a href="https://github.com/sponsors/jcbrand" target="_blank" rel="noopener">Github</a>,
+                       <a href="https://www.patreon.com/jcbrand" target="_blank" rel="noopener">Patreon</a>,
                        <a href="https://liberapay.com/jcbrand" target="_blank" rel="noopener">Liberapay</a> or
                        <a href="https://opkode.com/contact.html" target="_blank" rel="noopener">contact us</a>.
                     </p>

requirements.txt

@@ -1,3 +1,2 @@
-Sphinx==4.5.0
-docutils==0.17.1
+Sphinx==8.0.2
 sphinx-bootstrap-theme==0.8.1