Add note about RLZoo deprecation

[jeremiahpslewis]

PR Checklist

• Update NEWS.md?
• Unit tests for all structs / functions?
• Integration and correctness tests using a simple env?
• PR Review?
• Add or update documentation?
• Write docstrings for new methods?

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 1.12%. Comparing base (d470d48) to head (1684215).
⚠️ Report is 14 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #1062       +/-   ##
==========================================
- Coverage   32.35%   1.12%   -31.23%     
==========================================
  Files          73      73               
  Lines        2785    2748       -37     
==========================================
- Hits          901      31      -870     
- Misses       1884    2717      +833     

see 32 files with indirect coverage changes

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[HenriDeh]

Maybe we can add an @warn in the __init__ method of the package. This way users will be warned when loading it.

[jeremiahpslewis]

@HenriDeh What about an @info when loading RL.jl?

[HenriDeh]

That also works.