Add example script to update translation files

[hasecilu]

• Add bash script to include marked strings on
  • Python files (*.ts)
  • UI files (*.ui)

The workbench must mark the strings with translate() or QT_TRANSLATE_NOOP() on Python files.

Before merging maybe some other notes/comments should be added to the script to make maintainer or translator aware of someting. Maybe links to https://freecad.github.io/DevelopersHandbook/technical/translation.html or https://wiki.freecad.org/Translating_an_external_workbench?

This is already used on:

• https://github.com/FreeCAD/freecad.workbench_starterkit/pull/17
• https://github.com/Grubuntu/PieMenu/pull/27
• https://github.com/looooo/freecad.gears/pull/149
• https://github.com/Zolko-123/FreeCAD_Assembly4/pull/464
• https://github.com/shaise/FreeCAD_FastenersWB/pull/347
• https://github.com/instancezero/in3dca-freegrid/commit/17e4a188c5dd3d28b9af44e408bf7ae87df32c1f
• https://github.com/shaise/FreeCAD_SheetMetal/pull/301
• https://github.com/realthunder/FreeCAD_assembly3/pull/1332

[kaktusus]

Before merging maybe some other notes/comments should be added to the script to make maintainer or translator aware of someting.

Right suggestion. :grinning: I can add a few words about your script here in this repository. Now I will say that It is ro recommended solution by me :cactus: for both translators and developers of external workbenches. :1st_place_medal:

[hasecilu]

The previous script was made in my workflow as translator: update, translate, release.

With the new integration of external WB to Crowdin a new task is needed for maintainer so I made some changes.

• Enhance description of workflow
• Add missing locales (don't know how I missed them)
• -U flag for maintainer to update only main agnostic file
• -R flag for maintainer to release all translations
• -r & -u for translators to do the things they could do before
• Reorganize some functions
• Add help

Description:
        Create, update and release translation files.

Usage:
        ./update_translation.sh [-R] [-U] [-r <locale>] [-u <locale>]

Flags:
  -R
        Release all locales
  -U
        Update main translation file (locale agnostic)
  -r <locale>
        Release the specified locale
  -u <locale>
        Update strings for the specified locale

Maybe some links to some resources could be added?