Added Portuguese European (Portugal) pt language

[Ricardo-Simoes]

Took ptBR (Brazilian) as base, and added pt Portuguese European (Portugal). I need this to work fast since in my country schools and companies are closed and/or quarantine and people, students, and professors need an open-source solution for video conferencing, and advising the Portuguese goverment to adopt open source solutions

[jitsi-jenkins]

Hi, thanks for your contribution!
If you haven't already done so, could you please make sure you sign our CLA (https://jitsi.org/icla for individuals and https://jitsi.org/ccla for corporations)? We would unfortunately be unable to merge your patch unless we have that piece :(.

[jluisfa]

In meet.jit.si only the "Portuguese (Brazil)" option is there.
The Portuguese European (Portugal) option is not available

[damencho]

Yep, it wasn't added to https://github.com/jitsi/jitsi-meet/blob/master/lang/languages.json, I'll add it.

[damencho]

#8930

[jluisfa]

Now, in alpha.jitsi.net and beta.meet.jit.si, already appears "Language: Portuguese".
Thanks!

However, the text on the screen is not translated into Portuguese from Portugal.

I suggest a quick UI translation of the file jitsi-meet/lang/main-pt.json by adding:

+ "joinMeeting": "Participar da reunião"
+ "joinTooltip": "Participar da reunião"
+ "joinWithoutAudio": "Participar sem áudio"
+ "doNotShow": "Não mostre este ecrã novamente"
+ "lookGood": "O seu microfone está a funcionar corretamente"

+ "lonelyMeetingExperience": {
+        "youAreAlone": "Está sozinho na reunião",
+        "button": "Convidar outros"
+    }

+ "inviteMorePrompt": "Convide mais pessoas"