feat(gno.land): Implement markdown package

[sunspirit99]

From #2753

I keep this PR open to see if I am on the right approach. If it's suitable, I'll investigate to make further improvements and provide implementation examples in the Render() functions of some current demo realms to demonstrate the use of this package

To-do :

• Implement functionality for nested lists (both bullet and ordered) to provide more structure in the generated Markdown
• Ensure that each function has clear documentation comments, describing its purpose and usage

cc @moul

Contributors' checklist...

• Added new tests, or not needed, or not feasible
• Provided an example (e.g. screenshot) to aid review or the PR is self-explanatory
• Updated the official documentation or not needed
• No breaking changes were made, or a BREAKING CHANGE: xxx message was included in the description
• Added references to related issues and PRs
• Provided any useful hints for running manual tests
• Added new benchmarks to generated graphs, if any. More info here.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 60.95%. Comparing base (d3049ae) to head (6ac3db4).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2912      +/-   ##
==========================================
- Coverage   60.97%   60.95%   -0.02%     
==========================================
  Files         564      564              
  Lines       75273    75273              
==========================================
- Hits        45901    45886      -15     
- Misses      26005    26017      +12     
- Partials     3367     3370       +3     

Flag	Coverage Δ
contribs/gnodev	61.46% <ø> (ø)
contribs/gnofaucet	14.46% <ø> (-0.86%)	⬇️
gno.land	67.92% <ø> (ø)
gnovm	65.78% <ø> (ø)
misc/genstd	80.54% <ø> (ø)
misc/logos	19.88% <ø> (-0.36%)	⬇️

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