Add gif at top in the README showing how to generate projects with Django Keel

[CuriousLearner]

Adding a visual aid in the README showcasing how to generate projects with Keel.

It should demonstrate both the long way of choosing each prompt one by one, as well as the shorter way of using a single command to get a project.

[kanishka1804]

hi @CuriousLearner, i would like to work on this issue. Can you please assign it to me ?

[CuriousLearner]

Hi @kanishka1804 👋🏼

Please feel free to raise a PR.

[CuriousLearner]

We may use http://asciinema.org/ to generate the gif.