Define how we manage new contributions and issues in wis2box

[maaikelimper]

Dear Tom, could you help provide some guidance (to be documented once defined) with regards the following:

• how do we track issues from images built in repository outside of this one, namely (wis2box-api, wis2box-ui, wis2box-webapp, wis2downloader). Do we reference or move issues from these other repo's to the main repo ? Or should we move to have a "wis2box-project" to associate issues from different repositories to ?
• how do we manage contributions and issues from GitHub-users outside of the known team of developers ? (I add the label "security" as managing who can contribute to our code impacts security of our codebase)