[GENERAL] Missing localizations: SL (Slovenian), LLD (Ladin)

[abaumg]

Issue content

Apart from French (in the Aosta Valley) and German (in South Tyrol), also Slovene (in Trieste, Gorizia and Udine) and Ladin (in South Tyrol and Trentino) are co-official languages in Italy.

Currently, only the French and German localizations are included. The Slovene and Ladin localizations are missing.

[immuniopensource]

Hi @abaumg and thanks for your contribution. Since this issue is not strictly related to the iOS application I am moving it to the documentation repository as mentioned in the CONTRIBUTING file. Thanks for your understanding.