[docs] Add Introduction heading to Appendix B
[docs] Add Introduction heading to Appendix B

Change-Id: I2804d38d821f28e177e01b5778c5d432311a80e0
Closes-Bug: #1631323
(cherry picked from commit b5bb2a9397dcd25ba63b883eb8713fd8232d6fc6)

yanyao/newton,yanyao/newton