[mui-datatables] Muidatatables 2.1 (#35329)
[mui-datatables] Muidatatables 2.1 (#35329)

* added the 'empty' boolean to the MUIDataTableColumnOptions and 'React.ReactNode' to the 'customHeadRender' it still requires TableRow and TableCell

* added name and updated versions to most recent

* removed minor update notation

* fixed header notation

* added new line at the end of the doc

* reverted the typescript version as per request

* added the new onDownload function for version 2.1, increased version, sorted options alphabetically to easier find properties

mcliment/DefinitelyTyped,georgemarshall/DefinitelyTyped,dsebastien/DefinitelyTyped,georgemarshall/DefinitelyTyped,markogresak/DefinitelyTyped,georgemarshall/DefinitelyTyped,georgemarshall/DefinitelyTyped,dsebastien/DefinitelyTyped