ADD: SearchAlgo Optuna - general ray search space

[adamovanja]

this PR:

• adds optuna as search algorithm to be used
• adjusts launching script on slurm with one node and multiple nodes
• improves readme documentation

[codecov]

Codecov Report

Attention: Patch coverage is 20.00000% with 8 lines in your changes missing coverage. Please review.

Project coverage is 48.16%. Comparing base (7c6061e) to head (49c507f).

Files	Patch %	Lines
q2_ritme/tune_models.py	0.00%	8 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #26      +/-   ##
==========================================
- Coverage   48.39%   48.16%   -0.24%     
==========================================
  Files          17       17              
  Lines        1029     1034       +5     
  Branches      156      156              
==========================================
  Hits          498      498              
- Misses        520      525       +5     
  Partials       11       11              

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[adamovanja]

closing since this PR does not include Optuna with own search space which does not allow conditional search spaces - this way included in PR #27.

keeping this for reference in case at some point a more general search space is needed