Add dotenv to Miscellaneous section

[aspyatkin]

Hello, I would like to add dotenv project to Miscellaneous section.

It is a good practice to pass application configuration (e.g. db connection strings) via environment variables (12-factor app). But when you develop an application it won't be convenient to type all environment variables in terminal to launch your application (unless you are using some process management tool, however, that requires additional configuration). That's where dotenv project comes out. You can put all env. variables stuff in one file (.env) and load it with one line of code.