DOCS-1105: Add mlmodel extra for PySDK

[andf-viam]

Add notice that Python SDK users must now also install the mlmodel extra alongside the Python SDK in order to use the ML Model service.

• Notice to central Program and ML Model service reference pages
• Inclusion on tutorials that present Python code, and use the ML Model service (though none used the deprecated
  input_data or output_data nomenclature). Guess: no changes needed to these tutorials, besides additional dep install step now documentation.

[viambot]

Overall readability score: 56.2 (🟢 +0.01)

File	Readability
_index.md	30.05 (🟢 +0.45)
python-venv.md	70.07 (🟢 +0.28)
_index.md	58.53 (🟢 +2.79)
guardian.md	72.53 (🔴 -0.07)

View detailed metrics

🟢 - Shows an increase in readability
🔴 - Shows a decrease in readability

File	Readability	FRE	GF	ARI	CLI	DCRS
_index.md	30.05	32.57	15.37	20.5	13.53	8.34
	🟢 +0.45	🟢 +0.31	🟢 +0.14	🟢 +0.1	🔴 -0.06	🟢 +0.03
python-venv.md	70.07	49.21	8.01	9.8	11.13	6.56
	🟢 +0.28	🔴 -0.61	🔴 -0.05	🟢 +0	🔴 -0.01	🟢 +0.15
_index.md	58.53	49.04	11.21	13.6	10.21	7.12
	🟢 +2.79	🟢 +0.91	🟢 +0.5	🟢 +0.7	🟢 +0.36	🟢 +0.08
guardian.md	72.53	60.95	9.39	10.7	9.34	6.04
	🔴 -0.07	🟢 +0	🔴 -0.02	🟢 +0	🟢 +0	🔴 -0.01

Averages:

	Readability	FRE	GF	ARI	CLI	DCRS
Average	56.2	47.78	10.54	12.9	11.95	7.69
	🟢 +0.01	🟢 +0	🟢 +0	🟢 +0	🟢 +0	🟢 +0

View metric targets

Metric	Range	Ideal score
Flesch Reading Ease	100 (very easy read) to 0 (extremely difficult read)	60
Gunning Fog	6 (very easy read) to 17 (extremely difficult read)	8 or less
Auto. Read. Index	6 (very easy read) to 14 (extremely difficult read)	8 or less
Coleman Liau Index	6 (very easy read) to 17 (extremely difficult read)	8 or less
Dale-Chall Readability	4.9 (very easy read) to 9.9 (extremely difficult read)	6.9 or less

[njooma]

Looks good! A few comments on how the instructions might be redundant, but they will work!

[njooma]

installing viam-sdk[mlmodel] includes the base viam-sdk itself, so you don't need both commands here

[njooma]

Same as above, viam-sdk[mlmodel] includes the base SDK

[viambot]

You can view a rendered version of the docs from this PR at https://docs-test.viam.dev/2122/public