Clarify title filter behavior in Templating docs

[davidjb]

Summary

Proposed change:

This PR updates the Templating docs to correct the explanation of the behavior of title. Previously, the docs indicate that only the first character in a string will be upper-cased but the example (and behavior as I've just tested) is that title will upper-case each word in a string, not just the first character. For avoidance of doubt, https://jinja.palletsprojects.com/en/stable/templates/#jinja-filters.title clearly sets out the intended behavior.

Checklist

I've completed the checklist below to ensure I didn't forget anything. This makes reviewing this PR as easy as possible for the maintainers. And it gets this change released as soon as possible.

• Proposed change helps towards purpose of this project.
• Documentation is added / updated to describe proposed change.
• Tests are added / updated to cover proposed change.
• Changelog has an entry for proposed change (if user-facing fix or feature).

[przemub]

I've made another proposal (#1521) - sorry, I haven't seen yours. That one also specifies that the remaining letters will be turned lowercase.