updated developer guide

assets/DEVELOPER_GUIDE.md

@@ -5,8 +5,8 @@
 To contribute any feature to EVA, you must install from source.
 
 1. Install package and dependency manager PDM following the instructions [here](https://pdm-project.org/latest/#other-installation-methods).
-2. Run `pdm install -G "eval[dev]"` to install the development dependencies.
-2. Run `pdm run python` to run a Python script or start an interactive Python shell within the context of the PDM-managed project environment.
+2. Run `pdm install -G "dev"` to install the development dependencies. This will create a virtual environment in `eva/.venv`.
+3. Run `pdm run python` to run a Python script or start an interactive Python shell within the context of the PDM-managed project environment. Alternatively, you can also activate the venv manually with `source .venv/bin/activate`.
 
 PDM quick guide:
 - `pdm lock -G:all` to generate or update the pdm.lock file including all groups.
@@ -20,6 +20,10 @@ For more information about managing dependencies please look [here](https://pdm-
 
 For testing automation, we use [`nox`](https://nox.thea.codes/en/stable/index.html).
 
+Installation:
+- with brew: `brew install nox`
+- with pip: `pip install --user --upgrade nox` (this way, you might need to run nox commands with `python -m nox` or specify an alias)
+
 Commands:
 - `nox` to run all the automation tests. 
 - `nox -s fmt` to run the code formatting tests.