Translation for themes documentation is missing section

[lmeyer1]

About https://devdocs.prestashop.com/1.7/themes/reference/theme-translation/

Important pieces of information are missing:

• When a theme contains .xlf files, how does their content find the way into the translation database.
• How is the translation database working (which tables, relation to .xlf files)

The problem I'm having: My theme contains .xlf files, but none of the terms are known by the BO translation page.

[matks]

Added to https://github.com/PrestaShop/docs/issues/1324

[lmeyer1]

@matks Thanks

[lmeyer1]

When a theme contains .xlf files, how does their content find the way into the translation database.

There's a bug with this. I'll keep updated.