count(s) and term_frequency(s)

[jbesomi]

Texthero's hero.term_frequency(s) should be reanamed hero.count(s) as in reality it just count the term.
Because of that, we should add another function that implements hero.term_frequency that is: "(number of times term t appears in a document) / (Total number of terms in the document).

The distinctions between the two should be made clear in both docstring and both functions should have a "See Also" to let the user quickly move from one function documentation to the other.

Both implementations might be written using scikit-learn CountVectorizer.

[avinashbhat]

If I understand correctly, the existing term_frequency method has to be renamed to count without any modification except that in the docstring, and another term_frequency method needs to be defined?