[docs] Update the flow of the docs following installation.

Summary: Add some new documentation after installation.

Test Plan: View using docs viewer.

Reviewers: bengotow, mg

Differential Revision: https://review.inboxapp.com/D213
[api/ns] Move the ns_api route definition.
[git] Ignore vim temporary files.
[docs] Don't wordwrap.
[docs] Update the flow of the docs following installation.

Summary: Add some new documentation after installation.

Test Plan: View using docs viewer.

Reviewers: bengotow, mg

Reviewed By: mg

Differential Revision: https://review.inboxapp.com/D213