Add Persian translation

[ryonakano]

What Happened?

Originally reported by @pikhosh in the Translations Slack.

Persian translation for the website don't exist.

Steps to Reproduce

1. Open the website
2. Scroll down to display the language list
3. See Persian isn't listed

Expected Behavior

Persian language should be available as a possible selection.

OS Version

6.x (Odin)

Software Version

Latest release (I have run all updates)

Log Output

N/A

Hardware Info

N/A

[lewisgoddard]

We cleaned up languages that lacked a significant amount of translations, and since then the website doesn't appear to support Persian. https://l10n.elementary.io/projects/website/#languages We would need to generate new template files and add Persian to the list so translation can start.

[ryonakano]

Different from our desktop components, this repository doesn't seem to have translation templates and Weblate reports that as a warning so we've been disabling the feature of starting new language from the templates. It would be great if we could add templates and re-enable this function which would also allow translators themselves can start new translations of their languages!

[lewisgoddard]

This is blocked by #2955

[lewisgoddard]

Is this still something we want to add? I believe the list is in _backend/Lib/L10n.php

[lewisgoddard]

We have some languages like Punjabi with no translations, while some with full translations will never be shown because the website only allows translations that are specifically hard-coded in that list to be loaded. It might be worth going through and seeing which we should drop and which we should add.