Very light transmission-daemon installation fully based on the Debian packages.
By design, it will only run the transission daemon, exposing its standard port and exporting volumes for both the configuration and the data (including download) directories.
You can execute it with something like:
docker run -d -P --name transmission odiobill/transmission
Be aware that the default configuration allows connection by any IP address and with the default username/password pair, both set to transmission. To change this, you may want to run another (temporary) container that imports its volumes. Run it with:
docker run -i -t --name config_transmission --volumes-from transmission odiobill/transmission bash