Feedback from new nodes development in Nantes

[rienafairefr]

• The provided docker images are not amenable to be used behind a http proxy (which is the case when connected to the normal network in Polytech & Univ. Nantes : apt-get and pip fail, we should be able to provide a http_proxy env variable that is repercuted inside the docker container

• It's not mentioned that it's a good idea to python setup.py udev_rules_install, either before adding the new board class, or after creating a udev rule, if you're creating a udev rule for a new board.

• In the case a udev rule needs creating, people are on their own, we have some idea how to do it because we did it, but it's not something that is easy do to, we should document it.

• In the doc, we describe roughly how to build support for new nodes from scratch. But in many cases, the support for the *Link part is already there. If a new board doesn't use Daplink/JLink/StLink, then from-scratch is useful. Otherwise, it's just a distraction, we should directly explain and tell people to use the already provided bases classes (NodeJlinkBase, etc)

• DOCKER.md/INSTALL.md/DEVELOPER.md, a bit difficult to navigate many files that present kinda the same thing

• Some caveats for installation and usage of Docker in a Windows installation would be nice, we have some for mac os.