FEATURE: add a settings panel to edit mysite/lang/*.yml files from within CMS

[JorisDebonnet]

I was looking for this functionality, but can't find it anywhere. I feel like it should be quite doable to make this, and the Translatable module seems like a sensible place to add it to.

Not meant as a fully featured translation tool, just to be able to edit those values without needing access to them on the server.

Benefit:
If there's a word or sentence that appears on every page in the footer (or anywhere else), it's probably put there directly in a template from a i18n value, not from any page in the CMS. So if the content author wants to change that value, they have to ask the web developer, rather than being able to do it themselves.

[chillu]

Hey Joris, I think this is adding the kitchen sink to the translatable module - and it undermines the principle of SilverStripe where code in your webroot is managed via version control. I think your idea would make a nice module (e.g. storing user-editable yml files in assets/, or even changing the i18n class to load strings from the DB), but I don't think there's much point in adding this to the translatable module.