Share untranslated locales with relevant users and solicit help for translations in the frontend

[zackkrida]

Problem

Openverse currently has zero translations for, at the time of writing, 140 languages:

140 languages, alphabetized by English name

Afrikaans
Algerian
Amharic
Arabic
Aragonese
Armenian
Arpitan
Asturian
Azerbaijani
Azerbaijani
Balochi
Bashkir
Basque
Belarusian
Bengali
Bhojpuri
Bodo
Borana
Bosnian
Breton
Catalan
Cebuano
Chinese
Chinese
Cornish
Corsican
Dhivehi
Dzongkha
Emoji
English
English
Esperanto
Estonian
Faroese
Finnish
Fon
Frisian
Friulian
Fulah
Georgian
German
German
Greenlandic
Haitian
Hausa
Hawaiian
Hazaragi
Hebrew
Hungarian
Icelandic
Ido
Igbo
Irish
Javanese
Kabyle
Karakalpak
Kazakh
Khmer
Kinyarwanda
Kurdish
Kurdish
Lao
Ligurian
Limburgish
Lingala
Lombard
Lower
Luganda
Luxembourgish
Macedonian
Maithili
Malagasy
Malay
Maori
Mauritian
Mongolian
Montenegrin
Moroccan
Myanmar
N’ko
Nigerian
Norwegian
Occitan
Oriya
Ossetic
Panjabi
Papiamento
Papiamento
Pashto
Picard
Portuguese
Rohingya
Romansh
Sakha
Sanskrit
Saraiki
Sardinian
Scottish
Serbian
Shona
Shqip
Sicilian
Silesian
Sindhi
Sinhala
Slovenian
Somali
South
Spanish
Spanish
Spanish
Spanish
Spanish
Spanish
Sundanese
Swahili
Swati
Syriac
Tagalog
Tahitian
Tajik
Tamazight
Tamazight
Tamil
Tamil
Tatar
Thai
Tibetan
Tigrinya
Turkmen
Tweants
Upper
Urdu
Uzbek
Venetian
Vietnamese
Wolof
Xhosa
Yoruba
Zulu

We do not want these languages in our locale chooser because it suggests we offer translations in these languages. We removed them from the locale chooser in #4224.

However, as it stands, we do not have a way to:

1. Share with users who would like to use these languages that we could support them
2. Share with users who may like to contribute translations to these languages that they have the opportunity to do so.

Description

One solution I'd like to propose is that we store a list of the untranslated language codes in the frontend state, and display a dismissable banner to users with a matching Accept-Language header set:

Openverse is not yet translated into {language}. We need your help! If you would like to contribute translations, please see our welcome guide for translations.

We should also expand the contributor guidelines in that linked document to include basic instructions like "go to {glotpress page} and find your language to start contributing".

Alternatives

Additional context