Small docs update and an update for `start-stack.sh` with missing color
and if statment logic.
# What does this PR do?
1. Makes a small change to start-stack.sh to resolve this error:
```cmd
/home/aireilly/.local/lib/python3.13/site-packages/llama_stack/distribution/start_stack.sh: line 76: [: missing ]'
```
2. Adds a missing $GREEN colour to start-stack.sh
3. Updated `docs/source/getting_started/detailed_tutorial.md` with some
small changes and corrections.
## Test Plan
Procedures described in
`docs/source/getting_started/detailed_tutorial.md` were verified on
Linux Fedora 41.
51492bd9b6