docs: interactive variables in code samples

[thomasheartman]

This pr adds interactive (user-configurable) variables to the docs. They're added via a variable component.

As of now, this is a draft, and needs some further work / research.

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Coverage report

St.:grey_question:	Category	Percentage	Covered / Total
🟢	Statements	91.39%	4734/5180
🟢	Branches	80.27%	724/902
🟢	Functions	86.63%	1108/1279
🟢	Lines	91.31%	4636/5077

Test suite run success

789 tests passing in 116 suites.

Report generated by 🧪jest coverage report action from edada13a70157042046ec3fd6c80c37a737a280f

[stale[bot]]

This pull request has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[thomasheartman]

This is a long-running effort. I'll try and pin it for now.

[ivarconr]

closing due to inactivity.