Add documentation

Bug: 185121472
Test: doc-only change
Merged-In: I3c2563d4ae4e3715d0c6270344ba8f7ef067872f
Merged-In: I5fd68b209959043f6fe15ac34629c51233fea596
Change-Id: I5fd68b209959043f6fe15ac34629c51233fea596
  (cherry-picked from ag/14186082)
2 files changed