Adds code-owners for teams/projects. (#6266)
Adds code-owners for teams/projects. (#6266)

* Codeowner structure changes.

* Fixed typos.

* Added missing codeowners for suggestion project.

* Fixed typos.

* Added review changes.

* Added comment for explanation.

* Fixed typos.

kevinlee12/oppia,prasanna08/oppia,prasanna08/oppia,prasanna08/oppia,oppia/oppia,prasanna08/oppia,oppia/oppia,brianrodri/oppia,souravbadami/oppia,kevinlee12/oppia,brianrodri/oppia,souravbadami/oppia,kevinlee12/oppia,oppia/oppia,brianrodri/oppia,oppia/oppia,souravbadami/oppia,brianrodri/oppia,prasanna08/oppia,kevinlee12/oppia,souravbadami/oppia,brianrodri/oppia,kevinlee12/oppia,souravbadami/oppia,oppia/oppia