[data grid][docs] Add small edits to the overview page

[danilo-leal]

• [x] I have followed (at least) the PR section of the contributing guide.

Not a comprehensive review by any means, just quick wins. Some highlights:

• data grid/grid → Data Grid
• react → React
• MIT and Commercial versions → MIT and Commercial licenses
• Premium/Pro version → Premium/Pro plan

https://deploy-preview-13060--material-ui-x.netlify.app/x/react-data-grid/

[mui-bot]

Deploy preview: https://deploy-preview-13060--material-ui-x.netlify.app/

Updated pages:

• docs/data/data-grid/overview/overview.md
• docs/data/introduction/support/support.md

Generated by :no_entry_sign: dangerJS against d8a97d11b36ebbc4f4094d2caf04e8b1a208f891

[danilo-leal]

@samuelsycamore quick bump on this one as it's a fast/simple one! 😃