Include basic cSpell

[nschonni]

Problem to solve

Currently the template includes cSpell as part of the installation, but not the config or CI setup/instructions on how to use it.

Intended users

Further details

Proposal

• Re-add cSpell dependency (if it is removed in separate)
• Add base cspell.json file
• Add setup for French dictionaries and paths
• Add GitHub action for checking

Permissions and Security

What does success look like, and how can we measure that?

Links / references