Serializers file needs DocStrings

[markgbeckett]

The source file https://github.com/hangqianjun/python-intermediate-inflammation/blob/1721cab03f543646475d194cacf95c06e490e2df/inflammation/serializers.py does not contain any DocStrings comments, which would be helpful for someone who wished to contribute to the project.

[thespacedoctor]

This should take 30 mins.