fix: add quoting for newlines

[spaceone]

to make them distinguishable from escaped newline strings

Fixes: #49

[josheppinette]

@spaceone I just needed to get this all printed out to make sense. The new output (mostly the last line) looks good.

main

>>> logging.warning({"msg": "\n "})
at=WARNING msg="\n "
>>> logging.warning({"msg": r"\n "})
at=WARNING msg="\\n "
>>> logging.warning({"msg": "\n"})
at=WARNING msg=\n
>>> logging.warning({"msg": r"\n"})
at=WARNING msg=\n
>>> logging.warning({"msg": r"\n" + "\n"})
at=WARNING msg=\n\n

spaceone:fix/newline-quoting

>>> logging.warning({"msg": "\n "})
at=WARNING msg="\n "
>>> logging.warning({"msg": r"\n "})
at=WARNING msg="\\n "
>>> logging.warning({"msg": "\n"})
at=WARNING msg="\n"
>>> logging.warning({"msg": r"\n"})
at=WARNING msg=\n
>>> logging.warning({"msg": r"\n" + "\n"})
at=WARNING msg="\\n\n"