docs: use sphinxcontrib for the rst builder

Author: nedbat

doc/conf.py

@@ -39,7 +39,8 @@
     'sphinx.ext.ifconfig',
     'sphinxcontrib.spelling',
     'sphinx.ext.intersphinx',
-    'sphinx_rst_builder',
+    #'sphinx_rst_builder',
+    'sphinxcontrib.restbuilder',
     'sphinx.ext.extlinks',
     'sphinx.ext.napoleon',
     'sphinx_tabs.tabs',

doc/requirements.pip

@@ -5,10 +5,7 @@
 doc8==0.8.1
 pyenchant==3.2.0
 sphinx==3.4.3
-#sphinx-rst-builder==0.0.3
-# fails,
-# fixed with https://github.com/davidfritzsche/sphinx-rst-builder/pull/3
-git+https://github.com/nedbat/sphinx-rst-builder
+sphinxcontrib-restbuilder==0.3
 sphinxcontrib-spelling==7.1.0
 sphinx_rtd_theme==0.5.1
 sphinx-autobuild==2020.9.1