Merge duplicate batch processing docs

[rbeucher]

Summary

• remove the duplicate batch-processing mini-guide from getting started
• point readers to the dedicated batch processing reference page
• keep the ILAMB workflow as the worked batch example

Testing

• not run (docs-only change)

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 76.5%. Comparing base (6ebf88d) to head (551a27d).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@          Coverage Diff          @@
##            main    #429   +/-   ##
=====================================
  Coverage   76.5%   76.5%           
=====================================
  Files         30      30           
  Lines       5884    5884           
  Branches    1086    1086           
=====================================
  Hits        4499    4499           
  Misses      1145    1145           
  Partials     240     240           

Flag	Coverage Δ
unit	76.5% <ø> (ø)

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