Unintended Comments

It is pretty easy to accidentally write a comment instead of a specification, e.g.:

.. spec:

    --> Should be ".. spec::"

.. :mod

    --> Should be ".. mod::"

.. interface

    --> Should be ".. interface::"

.. :unit:

    --> Should be ".. unit::"

.. srs..

    --> Should be ".. srs::"

This extensions forbids the strings srs, spec, mod, interface and unit in the first line of a comment if there are no other non-word characters in this line.

Allowed comments:

..
    A nice module.
    --> Other non-word characters in first line.

..  A nice interface.
    --> Other non-word characters in first line.

..
    First line.
    spec
    --> Forbidden string not in first line.