Standardisation of sphinx docs page titles

This may be the nitpickiest issue I have ever raised, so should not be actioned unless there's strong agreement.

(from https://diamondlightsource.github.io/python-copier-template/main/how-to.html)

It annoys me that the titles for docs pages are not really standardised, Some Are Capitalised, some are not, some are prefixed with "How to" or similar. If there is a really easy check that can be added to the docs builds it might add a layer of consistency and professionalism. The hardest part, as ever when we talk about formatting, may be agreeing on which standard to use.

Review the example page at https://diamondlightsource.github.io/python-copier-template/main/how-to.html and the issue discussion first, since no source file or test is named. Confirm that the project has agreed on a title convention and identify the docs build entry point before scoping a check; done means the convention is explicit and the build consistently enforces it.

Written by the indexing model from the issue text.