Feature Request : Add option to skip title casing in toc item titles

[pvshn]

We use this extension to generate toc.yml for Python documentation using Sphinx. In this case, we want the toc titles to be exactly the same as that of the filename. This feature request is to add a configuration option to skip automatic title casing for toc titles.

We could generate an .override file but the feature I propose is more efficient.

[Ellerbach]

If you want to go for a PR with this addition, feel free to add it. So far, it's not really on the priority list.