[docs] Update README.md to match Introduction section of the docs

[samuelsycamore]

This PR updates the MUI X repo README to bring it up to date with the text from the Introduction section of the docs. All sections have been revised, and new sections have been added for installation instructions and detailed info on the different plans.

Before: https://github.com/mui/mui-x/blob/master/README.md
After: https://github.com/samuelsycamore/mui-x/blob/update-readme/README.md

[mui-bot]

These are the results for the performance tests:

Test case	Unit	Min	Max	Median	Mean	σ
Filter 100k rows	ms	441.3	699.8	501.5	543.36	92.947
Sort 100k rows	ms	664.3	1,129.1	809	896.34	157.034
Select 100k rows	ms	176	415.1	283.2	278.9	80.34
Deselect 100k rows	ms	168.3	264.1	209.8	208.98	32.715

Generated by 🚫 dangerJS against 4613fc1

[cherniavskii]

Suggested change

	Future plans and high-priority features and enhancements can be found in our [roadmap](https://mui.com/material-ui/discover-more/roadmap/).
	Future plans and high-priority features and enhancements can be found in our [roadmap](https://mui.com/x/introduction/roadmap/).

Link to MUI X roadmap instead?

[samuelsycamore]

Whoops! 😅

[oliviertassinari]

Off-topic

I didn't know we had these two different roadmap pages. https://mui.com/material-ui/discover-more/roadmap/#new-components talks about what the next components planned for MUI X, an information developers don't get on https://mui.com/x/introduction/roadmap/.

I guess we need a central place to talk about the next component (not necessarily on the docs, it could be private in notion) so that Core and X don't say they will build the same one.

How should we resolve this?

[samuelsycamore]

@oliviertassinari this sounds like another page that would be best suited for a companywide document—mui/material-ui#33514.

[joserodolfofreitas]

Thanks for this update, @samuelsycamore!

[mbrookes]

I do see the benefits of distinguishing the generic name for a control such as a "button", from the React component name "Button". It seems awkward to refer to a Button mid-sentence when referring generically to a button, and not to our specific React implementation.

For the example that sparked this discussion "Date and time pickers" seems fine to me.

[oliviertassinari]

It seems awkward to refer to a Button mid-sentence when referring generically to a button, and not to our specific React implementation.

@mbrookes Then I would be curious to get your perspective on these cases: #5780 (comment). It's no longer about the headers (what I felt we talked about here), but about how we reference these components in the body of the docs.

[samuelsycamore]

I'm going to go ahead and merge this as is, but we can continue the conversation about capitalization conventions and come back to those minor details later if needed.