DOC: Update the infrastructure guide

Include informaton about the workflow managing versions on gh-pages.

docs/devel/infrastructureguide.rst

@@ -33,10 +33,13 @@ extension also makes these scripts available as Jupyter notebooks.
 The documentation is hosted on `GitHub Pages <https://unidata.github.io/MetPy>`_. The docs are
 built automatically and uploaded upon pushes or merges to GitHub. Commits to ``main`` end up
 in our development version docs, while commits to versioned branches will update the
-docs for the corresponding version, which are located in the appropriately named subidrectory
+docs for the corresponding version, which are located in the appropriately named subdirectory
 on the ``gh-pages`` branch. We only maintain docs at the minor level, not the bugfix one.
 The docs rely on the ``pydata-sphinx-theme`` package for styling the docs, which needs to be
-installed for any local doc builds.
+installed for any local doc builds. The ``gh-pages`` branch has a GitHub Actions workflow that
+handles generating a ``versions.json`` file that controls what versions are displayed in the
+selector on the website, as well as update the ``latest`` symlink that points to the latest
+version of the docs.
 
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 Other Tools