DEV: Mount plugin symlinks to dev docker container (PR #8002)

When developing using docker, in order to support symlinks in the plugins/ directory, this reads the symlinks’ values and mounts them to the dev docker container.

Tested in macOS 10.14.5 and Ubuntu 18.04.

Open to suggestions, thanks!

GitHub

You’ve signed the CLA, xrav3nz. Thank you! This pull request is ready for review.

This looks good to me, fancy, I like how you docker running part. :+1: