Merge pull request #2254 from jgable/spellingFix

Spelling fix for "Testing Flux Applications"
Merge pull request #2237 from markhovskiy/patch-1

fix typos in "Testing Flux Applications"
Merge pull request #2236 from zpao/rm-flux-docs

Conflicts:
	docs/docs/flux-todo-list.md
[docs] Use subitem in new nav generation