[7.x] [DOCS] Clarify indexing a runtime field (#77117)#77139

Merged

lockewritesdocs merged 1 commit intoelastic:7.xfrom lockewritesdocs:backport/7.x/pr-77117

Sep 1, 2021

+14-8

Commits on Sep 1, 2021

[DOCS] Clarify indexing a runtime field (elastic#77117 )
Adam Locke
committed