Fix two typos in database transactions docs

In practice, this feature simply wraps every view function in the :func:`atomic`

decorator described below.

Note that only the execution of your view in enclosed in the transactions.

Middleware run outside of the transaction, and so does the rendering of

Note that only the execution of your view is enclosed in the transactions.

Middleware runs outside of the transaction, and so does the rendering of

template responses.

.. versionchanged:: 1.6