Add `make pre` step

Feel free to incorporate this better in other sections.
Fix manifest

Run `make pre` to check MANIFEST
Update Releasing.md [ci skip]
Update overview.rst
Merge pull request #941 from driscollis/patch-1

Update overview.rst
Update tutorial.rst

Just a couple grammatical fixes
Merge pull request #944 from driscollis/patch-2

Update tutorial.rst