Option to have API Token in config file

[bof]

It's a bit inconvenient for controlled deployment to a flock of machines, to have two files - .netrc + .config.yml - to deploy along with each other to have jira-cli work.

Idea would be

• add an option to have API Token in config file, along with login and server
• maybe as a precaution, check perms to be restrictive, in that case (user readonly)
• during "jira init" after having asked for server + login, if no token is present in environment or from .netrc, prompt the user to paste one + put it into the config file
• and maybe provide a "jira config edit (server|login|password)" option to change any of these, at a later time