Make docstring formatting consistent

[neubig]

Currently the format of our docstrings is not consistent. I'd suggest following the format in ResidualLSTMEncoder, as it seems to be the most thoroughly documented. We should also add the documentation style to the README.md or some other coding style document.

Update: To be more clear -- This means "use double quotes for docstrings" and "mark parameters as @param"

[neubig]

Update again: perhaps we should follow a previous convention. How about either:

• numpy style Python docstrings: http://sphinxcontrib-napoleon.readthedocs.io/en/latest/example_numpy.html
• Google style Python docstrings: http://sphinxcontrib-napoleon.readthedocs.io/en/latest/example_google.html

Any preference?

[neubig]

Sorry about the spam. Here is a good answer on stack overflow: http://stackoverflow.com/questions/3898572/what-is-the-standard-python-docstring-format

The Google and Numpy formats seem too verbose, so perhaps it'd be best to go with reST format used in Devendra's files. I'll go ahead with that.

[neubig]

Should be fixed by 4c14422