[docs] Unify multi-filtering introduction with the multi-sorting introduction

[flaviendelangle]

No description provided.

[mui-bot]

These are the results for the performance tests:

Test case	Unit	Min	Max	Median	Mean	σ
Filter 100k rows	ms	223.9	396.1	283.7	288.7	64.028
Sort 100k rows	ms	418.4	801.1	721.3	659.64	144.048
Select 100k rows	ms	153.6	253.8	187.5	198.14	33.496
Deselect 100k rows	ms	114.7	214.5	140.6	160.92	39.332

Generated by 🚫 dangerJS against f040566

[m4theushw]

Doesn't look vague this "Single and multi-filtering" section? It only contains a warning. Maybe we kill it and move the message to below the first demo in the page. I understand we want to say that there're two types of filtering, but we already used the single filtering for the first demo.

[flaviendelangle]

@m4theushw that's pretty much what I've done before this PR
But for the sorting, @joserodolfofreitas prefers to have a direct anchor to the "multi sorting" and for me both pages should be identical on that regard.

[joserodolfofreitas]

Doesn't look vague this "Single and multi-filtering" section? It only contains a warning. Maybe we kill it and move the message to below the first demo in the page. I understand we want to say that there're two types of filtering, but we already used the single filtering for the first demo.

We're changing it to add the blue cube to the pro feature, and I think the warning box, although arguably redundant, highlights a big difference on the community vs pro in a very clear way, so I thought that we should leave it.

[github-actions]

This pull request has conflicts, please resolve those before we can evaluate the pull request.

[siriwatknp]

👋 The migration PR has been merged.

Please follow these steps to make sure that the contents are all updated. (Sorry for the inconvenience)

1. pull latest master from upstream to your branch
2. if your PR has changes on the *.md or demo files, you are likely to encounter conflict because all of them have been moved to the new folder.
   2.1 revert the change on those markdown files you did
   2.2 pull latest master from upstream (you should not see conflict)
   2.3 make the changes again at docs/data/data-grid/*
3. run yarn docs:api
   • you might see the changes in docs/pages/x/api/data-grid/* if your PR touches some of the components
   • it is okay if there is no changes

If you are struggle with the steps above, feel free to tag @siriwatknp