improved CONTRIBUTING.md as I used it

CONTRIBUTING.md

@@ -80,24 +80,6 @@ virtualenv /path/to/venv
 source /path/to/venv/bin/activate
 ```
 
-### Install the Project Dependencies
-
-```
-pip install -r requirements.txt
-```
-
-If you want to contribute to the project or run tests, install the development dependencies:
-
-```
-pip install -r requirements-dev.txt
-```
-
-If you want to use the HuggingFace embedding models, install the additional requirements:
-
-```
-pip install -r requirements-hf-embed.txt
-```
-
 ### Install the Project in Editable Mode
 
 This step allows you to make changes to the source code and have them take effect immediately without reinstalling the package.
@@ -106,6 +88,22 @@ This step allows you to make changes to the source code and have them take effec
 pip install -e .
 ```
 
+### Install the Project Dependencies
+
+```
+pip install -r requirements.txt
+```
+
+For development, at least install the development dependencies:
+
+```
+pip install -r requirements/requirements-dev.txt
+```
+
+Consider installing other optional dependencies from the `requirements/` directory, if your development work needs them. 
+
+Note that these dependency files are generated by `./scripts/pip-compile.sh` and then committed. See [Managing Dependencies](#managing-dependencies).
+
 ### Install Pre-commit Hooks (Optional)
 
 The project uses pre-commit hooks for code formatting and linting. If you want to install and use these hooks, run:
@@ -118,13 +116,21 @@ This will automatically run the pre-commit hooks when you commit changes to the
 
 Now you should have a fully functional development environment for the Aider project. You can start making changes, running tests, and contributing to the project.
 
+### Handy Opinionated Setup Commands for MacOS / Linux
+
+Here's an example of following the setup instructions above, for your copy/paste pleasure if your system works the same. Start in the project directory.
+
+```
+python3 -m venv ../aider_venv \
+ && source ../aider_venv/bin/activate \
+ && pip3 install -e . \
+ && pip3 install -r requirements.txt \
+ && pip3 install -r requirements/requirements-dev.txt
+```
+
 ### Running Tests
 
-To run the project's tests, use the following command:
+Just run `pytest`.
-
-```
-python -m unittest discover -s aider/tests
-```
 
 ### Building the Docker Image
 
@@ -211,11 +217,12 @@ The project uses `pytest` as the testing framework, which is installed as a deve
 pip install -r requirements-dev.txt
 ```
 
-### Dependencies
+### Managing Dependencies
 
-When introducing new dependencies, make sure to add them to the appropriate `requirements.in` file (e.g., `requirements.in` for main dependencies, `requirements-dev.in` for development dependencies). Then, run the following command to update the corresponding `requirements.txt` file:
+When introducing new dependencies, make sure to add them to the appropriate `requirements.in` file (e.g., `requirements.in` for main dependencies, `requirements-dev.in` for development dependencies). Then, run the following commands to update the corresponding `requirements.txt` file:
 
 ```
+pip install pip-tools
 ./scripts/pip-compile.sh
 ```
 
@@ -238,4 +245,3 @@ pre-commit will then run automatically on each `git commit` command. You can use
 ```
 pre-commit run --all-files
 ```
-```