feat: Add dev docker setup

[mr-karan]

Closes #562

• Created a dev/ folder with all the dev-docker specific files.
• The dev-docker setup is in such a way that the local app folder is mounted inside the container. This trick helps us to not do a docker build everytime there's a change in frontend/backend code.
• For frontend changes, since vue is automatically watching for changes, the live changes are seen in real time.
• For backend changes, since the Go app needs to be compiled, simply quit the current running setup and run make dev-docker again. That will run make run again, which would have new changes.
• There's a make init-dev-docker to run the DB Migrations for first time install.

These instructions are also inside dev/README.md.

P.S. I'd to create a new make target (run-backend-docker), simply because I don't know a better way of passing a different config file (dev/config.toml) to the go run argument in the existing run target. Hope the small amount of copy-paste is fine here.