GDAL cli cookbook

[geographika]

A new draft of the cookbook, replacing #13810. This approach avoids adding examples directly to the page, but instead links to examples on the relevant command pages using the custom Sphinx directive updated in #14007.

Other changes:

• added several new examples
• added a note about use of the jq tool for parsing JSON output (and updated URL)
• updated spelling list as example titles appear on other pages

I ran through a few different design choices for the layout, before setting on this approach inspired by the Sphinx FAQs.

Other options I tried included:

:Q: How do I buffer geometries?
:A: :example:`gdal-vector-buffer-1km`

and:

.. rubric:: Frequently Asked Questions

How do I get the GDAL version?
    :example:`gdal-version`.

@dbaston I modified the Examples, directive to show the :title: rather than the autogenerated page and example number. Let me know your thoughts on this.

Automated titles:

Updated to use example titles:

Other modifications to the extension were to handle example titles that included formatting e.g. literals. If reverting to the original automated :ref: titles then the extension needs to use .astext() or the doc pages end up formatted as <literal>gdal vector buffer</literal>.

example_doc_title = str(env.titles[example.docname].children[0].astext())

[rouault]

@geographika is the Draft status still valid or can that be merged?