Add support for RTL strings

[benoit74]

Fix #54

Changes:

• download RTL plugin in scraper thanks to openzim.toml / hatch-openzim mechanisms ; use RTL plugin in UI JS

Other changes:

• Move from --assets to --dl to stop confusion with the assets folder present in the scraper source code
  • include simplification of ZIM files layout: all assets from assets folder are placed in assets path in the ZIM
• Fix issues around favicon

[codecov]

Codecov Report

❌ Patch coverage is 5.26316% with 36 lines in your changes missing coverage. Please review.
✅ Project coverage is 32.07%. Comparing base (f888537) to head (1f2f6e0).
⚠️ Report is 5 commits behind head on main.

Files with missing lines	Patch %	Lines
scraper/src/maps2zim/processor.py	5.55%	34 Missing ⚠️
scraper/src/maps2zim/entrypoint.py	0.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #68      +/-   ##
==========================================
- Coverage   32.10%   32.07%   -0.03%     
==========================================
  Files          11       11              
  Lines         978      982       +4     
  Branches      131      132       +1     
==========================================
+ Hits          314      315       +1     
- Misses        653      656       +3     
  Partials       11       11              

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