Creating anonymous authentication accounts support

can you add Creating anonymous authentication accounts support for the package
the package already awesome and will be better if we add anonymous user that can read the data and the fire store

[DamenTheDev]

#398 For the time being, you can manually add it by following instructions in the Firebase documentation: https://firebase.google.com/docs/reference/rest/auth/#section-sign-in-anonymously

the pyrebase4 package provide this