Dev mode instructions not clear

### Description of the issue

A clear and concise description of the issue.
If you follow the dev mode instructions `cd dev/prod rushx dev-server` login doesn't work as it can't access localhost:3000. Do you need to run everything from the Build and run section to then run dev? This isnt clear in the readme

### Your environment

* Version of huly
* Browser (and version)
* Your operating system (and version)

### Steps to reproduce

Please produce the steps for us to reproduce this issue.

### Expected behaviour

Tell us what should happen. The following the development instructions should lead to a live-reload applications that fully functions

### Actual behaviour

Tell us what happens instead (include screenshots or logs).

### Possible solutions

(Not obligatory)
If you know how to fix the bug, please describe your solution here.

_{Huly®: UBERF-6688}