Terminology: Pull request reviewer vs assignees on Github

[Lars Kiesow]

Hi everyone,
looking at the first two weeks of Opencast on Github, things seem to go
quite smoothly. One thing I was asked multiple times, however, is how
taking a pull request as a reviewer works since it is a bit different
from Bitbucket. Here is what I think makes sense based on the features
Github offers:

- There is no need for the `//review//` at all
- Github pull requests can be assigned to one person. Hence, it makes
sense to use this to identify the *official reviewer* who ultimately
merges the pull request once the review is done.
- Multiple people can be a reviewer and start/finish their individual
reviews as well as approve a pull request. You can also request
someone as a reviewer. Github usually makes some suggestions based on
the people which have worked on the specific part of the code before.

So, assign yourself to a pull request when you want to be the official
reviewer but feel free to use the reviewer feature as well.

Best regards,
Lars