Add `dev` scripts to `package.json` in Tutor supported MFEs

[brian-smith-tcril]

MFE development outside of docker with Tutor is possible (and documented as of openedx/frontend-app-learning#1472).

We should update all Tutor supported MFEs so npm run dev works for local development with Tutor!

### Tasks
- [ ] [Authn](https://github.com/openedx/frontend-app-authn/)
- [x] [Authoring](https://github.com/openedx/frontend-app-authoring/) https://github.com/openedx/frontend-app-authoring/pull/1364
- [ ] [Discussions](https://github.com/openedx/frontend-app-discussions/)
- [ ] [Account](https://github.com/openedx/frontend-app-account/)
- [ ] [Communications](https://github.com/openedx/frontend-app-communications/)
- [ ] [Gradebook](https://github.com/openedx/frontend-app-gradebook/)
- [x] [Learner Dashboard](https://github.com/openedx/frontend-app-learner-dashboard/) https://github.com/openedx/frontend-app-learner-dashboard/pull/530
- [x] [Learning](https://github.com/openedx/frontend-app-learning/) https://github.com/openedx/frontend-app-learning/pull/1472
- [ ] [ORA Grading](https://github.com/openedx/frontend-app-ora-grading/)
- [ ] [Profile](https://github.com/openedx/frontend-app-profile/)

[regisb]

I suggest we primarily update the instructions in tutor-mfe, and then link to the instructions from every MFE. Note that the proposed tutor dev start lms cms mfe command will work only partially, as it will not start other services, such as notes, aspects, etc.