DOC: pd.read_msgpack not in API index

[skycaptain]

If I have not overlooked anything, it seams that pd.read_msgpack does not show up in the API reference index.

[chris-b1]

Yep, PR to fix welcome!

[tadiseshan]

If no one else is working on this, I'll start working on a PR!

[jorisvandenbossche]

@taraadiseshan Go for it! If you have any questions, just ask here or at https://gitter.im/pydata/pandas