docs(python): Add Polars & LLMs page to the user guide

[braaannigan]

Closes #21110

This PR covers the user guide component. An llms.txt requires a separate PR

[braaannigan]

@ritchie46 Cheers, I just learned something important about cursor integration, I want to quickly add that in as well

[codecov]

Codecov Report

Attention: Patch coverage is 41.19948% with 451 lines in your changes missing coverage. Please review.

Project coverage is 79.76%. Comparing base (b50f758) to head (2be2036).
Report is 14 commits behind head on main.

Files with missing lines	Patch %	Lines
crates/polars-stream/src/nodes/joins/equi_join.rs	0.00%	309 Missing ⚠️
crates/polars-io/src/csv/read/parser.rs	0.00%	80 Missing ⚠️
crates/polars-stream/src/nodes/io_sources/csv.rs	67.56%	24 Missing ⚠️
crates/polars-expr/src/hash_keys.rs	0.00%	17 Missing ⚠️
crates/polars-sql/src/context.rs	71.42%	16 Missing ⚠️
crates/polars-utils/src/select.rs	0.00%	3 Missing ⚠️
crates/polars-stream/src/nodes/io_sources/ipc.rs	98.07%	1 Missing ⚠️
.../polars-stream/src/nodes/io_sources/parquet/mod.rs	97.22%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #21160      +/-   ##
==========================================
- Coverage   79.88%   79.76%   -0.13%     
==========================================
  Files        1593     1594       +1     
  Lines      227649   228142     +493     
  Branches     2600     2600              
==========================================
+ Hits       181858   181974     +116     
- Misses      45194    45571     +377     
  Partials      597      597              

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[braaannigan]

Re-opened as #21218