* Improved Bash Logger
This is a first step towards having robust Bash scripts in the runner images. The changes _could_ be considered breaking, depending on our backwards compatibility definition.
* Fixed Log Formatting Issues
Co-authored-by: Callum Tait <15716903+toast-gear@users.noreply.github.com>
Changes:
- Switched to use `jq` in startup.sh
- Enable docker registry mirror configuration which is useful when e.g. avoiding the Docker Hub rate-limiting
Check #478 for how this feature is tested and supposed to be used.