Factorise la conversion des commentaires en Markdown

[Guts]

No description provided.

[codecov]

Codecov Report

Merging #90 (ee6353a) into main (04f75ed) will decrease coverage by 0.25%.
The diff coverage is 62.50%.

@@            Coverage Diff             @@
##             main      #90      +/-   ##
==========================================
- Coverage   68.47%   68.22%   -0.25%     
==========================================
  Files          24       24              
  Lines        1126     1133       +7     
  Branches      208      209       +1     
==========================================
+ Hits          771      773       +2     
- Misses        307      312       +5     
  Partials       48       48              

Impacted Files	Coverage Δ
geotribu_cli/subcommands/comments_broadcast.py	31.70% <ø> (-0.83%)	⬇️
geotribu_cli/subcommands/comments_latest.py	66.66% <ø> (ø)
geotribu_cli/constants.py	88.34% <62.50%> (-4.29%)	⬇️