Fields in table representation

[yasinrawther]

Here I have added the feature of fields with the table representation. So you can use Table representation to make your fields list in the documentation clear. So We can change representation by adding single line inside the REST_FRAMEWORK_DOCS in settings.py. And also show max_length field in table representation. Sample output I attached here.

[soraphis]

change:

if field.__dict__.get('max_length', '-') != None else '-')

to

if field.__dict__.get('max_length', '-') is not None else '-')

(to fulfill flake8 requirements)

[yasinrawther]

Committed the changes for flake8 requirements