Replace \n by <br> in table to avoid a poorly rendering for the table in markdown

[EmGarr]

docstring_parser has been a nice introduction which allows the usage of Google format.

However, the rendering of the table isn't convincing.

If my dosctring is written as follow:

   """
    Arguments:
        weights: a list of Numpy arrays. The number
            of arrays and their shape must match
            number of the dimensions of the weights
            of the layer (i.e. it should match the
            output of `get_weights`).
    """

The doc will be the following:

The issue is that \n isn't supposed to be used in a table with markdown. <br> could be used instead.

In this PR, I propose to do a quick modification of text.makoin order to replace the \nby <br>to fix the issue.

I don't really know the codebase. If you have a better fix, I'll be happy to do it.