Move out the docker information - docker README is now in the docker repository, update links - manual install instructions are now in the docs (https://github.com/e-mission/e-mission-docs/pull/53), delete + update links - editing source inside docker container is moved to the docker README (https://github.com/e-mission/e-mission-docker/pull/2), so moving it out of here (commit: 6aa1d8ae39bccf98036e26c42d33a207c531f8c9)