Add an entry point to generate an entry from a tweet (URL).

[joaopalmeiro]

References:

• http://docs.tweepy.org/en/latest/index.html.
• https://github.com/ryneches/tweet2bibTeX/blob/master/tweet2bibTeX/__init__.py.
• https://apastyle.apa.org/style-grammar-guidelines/references/examples/twitter-references.
• https://pybit.es/persistent-environment-variables.html.

Mix between APA and Wikipedia styles, as well as adaptation of some fields of BibLaTeX:

@online{tweet-karpathy,
	title        = {When you sort your dataset descending by loss you are guaranteed to find something unexpected, strange and helpful.},
	author       = {Andrej Karpathy},
	url          = {https://twitter.com/karpathy/status/1311884485676294151},
	note         = {[Online; accessed 8-October-2020]},
	authortype   = {[@karpathy]},
	organization = {Twitter},
	date         = {2020-10-02}
}