[7.1][DOCS] Moves Watcher content into Elasticsearch book (#47147)#47386

Merged

lcawl merged 1 commit intoelastic:7.1from lcawl:71-mv-watcher

Oct 1, 2019

+529-435

Commits on Oct 1, 2019

[DOCS] Moves Watcher content into Elasticsearch book (elastic#47147 )

lcawl
and
jrodewig
committed