Migrate 'Configuring the Open edX Platform'

[jswope00]

Legacy Configuring the Open edX Platform contains many guides for enabling certain features like course certificates, entrance exams, course prerequisites, etc.

Configuration items that are relevant to Open edX should be migrated to docs.openedx.org.

Additionally, the legacy guides are out of date (they reference things like lms.yml and cms.yml) and should be updated.

References across the org should be updated: https://github.com/search?q=org%3Aopenedx+%22edx.readthedocs.io%2Fprojects%2Fedx-installing-configuring-and-running%2F%22&type=code

[sarina]

Address #830 for all links to this guide when doing the migration