Update 'Getting Started' to account for missing 'overseer.schema'

[dfornika]

The getting started instructions include the following:

(require '[overseer.schema])
(overseer.schema/install (d/connect uri))

...but the overseer.schema namespace no longer exists. How can the user load the schema into datomic?

[andrewberls]

Hey @dfornika sorry about this; we've revamped Overseer's API quite a bit to support pluggable storage backends (MySQL is now supported in addition to Datomic) and the docs haven't been updated accordingly. I'll do my best to get those updated and get back to you!

[dfornika]

Oh, that's exciting. Looking forward to trying it out once the docs are updated.