Prune unmaintained languages

[jbrazio]

Removes unmaintained Spanish language variations:

• Aragonese (language_an.h)
• Basque-Euskera (language_eu.h)
• Catalan (language_ca.h)
• Galician (language_gl.h)

For now we still keep unmaintained:

• Bulgarian (Missing Bulgarian translation #3348)
• Finnish (Missing Finnish translation #3355)
• Polish (Missing Polish translation #3360)

Closes: #3357, #3354, #3349, #3347

This PR has the side effect of move example_configurations/Felix/Configuration_DUAL.h into its own DUAL folder and renaming it to Configuration.h. This is so the config file can be catched when doing mass edits based on find . -name Configuration.h | xargs <something>.

[thinkyhead]

Aww… I love being able to tell people Marlin supports "dozens" of languages.
Now I'll be an even bigger liar! 😄

[jbrazio]

Well these are non mainstream languages..
(I'm trying to see where they are hidden so we can convince them to update the language files :-)

[thinkyhead]

@jbrazio It probably will happen that after 1.1.0 release, the language maintainers will appear with patches. But maybe not before. Have you messaged the individuals who made the most recent commits to these languages already?

[jbrazio]

@thinkyhead All of them have been pinged, if no reply within a week this PR should be merged.
All of the languages on this PR had the first commit and no more updates on the native language, all the following updates on the blame history were English additions.

[rafacouto]

Galician syncronized at the moment. Thank you for pinging to me 👍

[jbrazio]

Thank you for your contribution @rafacouto !

[CONSULitAS]

@jbrazio
@rafacouto
We have discussed the idea of language care takers before.

Should we add a header to maintained translations with the care taker(s) like in https://github.com/MarlinFirmware/Marlin/blob/RC/Marlin/example_configurations/K8200/Configuration.h#L23 ?

So it would be easier to find natives for the next update...

[jbrazio]

I like the idea, but how about using github teams ?
This way we could ping them with the "@" thing.

@MarlinFirmware/lang-en
@MarlinFirmware/lang-pt
@MarlinFirmware/lang-de
etc

Or have a unique @MarlinFirmware/localization-team with all the lang people inside, usually it's more than one lang file that needs updating.

@Roxy-3DPrintBoard

[Blue-Marlin]

In my opinion the unmaintained languages should be kept in.
For German i know there are dozens of 'personal' translations out there. The hurdles are not, to change some translations for your self but to judge is they are acceptable for a bigger audience and to do the PR with github. Removing the examples for the languages would make the hurdle for these 'personal' translation much higher.

[rafacouto]

I am going to give it a try to this script: https://github.com/nevik/gitwatch

Another option could be a webhook to watch changes on the main language file and send an email to the maintainers declared in the header of the language files (@CONSULitAS ' idea).

[jbrazio]

Closing due the creation of @MarlinFirmware/language-team.
Still some languages are problematic and lack maintainers.