1. Update URLs according to OpenStack document migration
2. Update the dead and outdated links
3. Optimize (e.g. http -> https)
Change-Id: Ib1ff6536072715ad81cbd1f53097b53e4adad95d
Adding the overview document and changed a few documents to make
the docs better.
Change-Id: Ia1fd7f037f85cc1363678f16232c1d9371fdb292
Partial-Implements: blueprint meteos-docs