docs: Update tox.ini to build the "users" sphinx instance

Related to T3388

tox.ini

@@ -14,6 +14,7 @@ deps =
 setenv =
   SWHPKGDIR = {envsitepackagesdir}/swh
 commands =
+  {envpython} -m pifpaf run postgresql -- make -C users {posargs:html}
   {envpython} -m pifpaf run postgresql -- make -C docs {posargs:html}
 
 [testenv:sphinx-dev]
@@ -24,6 +25,7 @@ install_command = make pip-install-swh-dev {packages}
 setenv =
   SWHPKGDIR = {envsitepackagesdir}/swh
 commands =
+  {envpython} -m pifpaf run postgresql -- make -C users {posargs:html}
   {envpython} -m pifpaf run postgresql -- make -C docs {posargs:html}
 
 [testenv:black]

[Phabricator Migration user]

Some references in the commit message have been migrated:

• T3388 is now #3388 (closed)