Betterjsondb

• Added file checker.
If connected file not exists library will create it and write `{}` to it.
• Added module `warnings` for future. It wiil warn you in console if something gets bad, but not critical for work.

- Added ability to get full dictionary of file.
py
import betterjsondb

db = betterjsondb.connect(file="tests.json", prefix="~")

print(db.get("all"))

- Added some typehints (hellowfacey, hi!).
py
... -> typing.Union[bool, None]