Improvements in README.md

[TwistingTwists]

As a newbie to Elixir, I realised the README.md could be organised better - changing the ordering of few sections + highlighting few more things.

Shall I send a pull request with requisite changes?

[rockneurotiko]

Sure! All help is welcome, and improving the documentation is one of the most important parts.

Just as a tip, if you are going to participate in the hacktoberfest (https://hacktoberfest.digitalocean.com/) wait until october 1st so the PR counts 😉

[TwistingTwists]

If you could list a few more issues where help is needed, I can look forward to working on them during hacktoberfest.

I will be using this awesome library for upcoming month.