Split "email" field in the JSON files

[kud1ing]

Currently the email addresses can be easily harvested from the JSON files on the GitHub page.
Instead of

"email": "foo@bar.com",

you could split the addresses like

"email_user": "foo",
"email_domain": "bar.com",

which would require more effort from the harvester.

[nrc]

I thought about some obfuscation here, but I think I prefer to leave it up to the user - the email addresses are in no way verified, so the user can put the domain in the notes, or use foo at bar dot com, etc. For those that don't mind the email address being publicly visible, the mailto link is pretty useful.