[Docs] Refactor theming document with improved header for Themers and better section ordering with import dependencies -> how to use them -> examples. (#7240)
[Docs] Refactor theming document with improved header for Themers and better section ordering with import dependencies -> how to use them -> examples. (#7240)

Refactor theming document with improved header for Themers and better section ordering with import dependencies -> how to use them -> examples.
Improves https://github.com/material-components/material-components-ios/commit/5c14dca53aadad1005923164097b63ded179b123 (#7210).
material-components/material-components-ios,material-components/material-components-ios,material-components/material-components-ios,material-components/material-components-ios,material-components/material-components-ios