README, removed applications section

[juanpabloaj]

Maybe modify the application section is not necessary.

I tried this package on elixir 1.14.0 without modify the application section and it works.

I followed this tutorial

https://dockyard.com/blog/2020/01/31/state-timeouts-with-gen_statem

More details:

https://www.amberbit.com/blog/2017/9/22/elixir-applications-vs-extra_applications-guide/