Add development section to installation docs

Author: kks32

docs/installation.md

@@ -21,38 +21,67 @@ import dapi
 print(dapi.__version__)
 ```
 
-## Development version
+## Update
+
+```bash
+pip install --upgrade dapi
+```
+
+## Development
+
+### Install the dev branch
+
+To test unreleased features from the `dev` branch:
 
 ```bash
 pip install git+https://github.com/DesignSafe-CI/dapi.git@dev
 ```
 
-Or in a notebook:
+Or in a DesignSafe Jupyter notebook:
 
 ```python
 %pip uninstall dapi --yes
 %pip install git+https://github.com/DesignSafe-CI/dapi.git@dev --quiet
 ```
 
-## Local editable install
+Restart the kernel after installing.
+
+### Local editable install
+
+For local development where changes take effect immediately:
 
 ```bash
 git clone https://github.com/DesignSafe-CI/dapi.git
 cd dapi
+git checkout dev
 pip install -e .
 ```
 
-### Set up pre-commit hook
+### Pre-commit hook
 
-The repo includes a pre-commit hook that auto-formats with `ruff format` and blocks commits that fail `ruff check`:
+The repo includes a pre-commit hook that auto-formats code with `ruff format` and blocks commits that fail `ruff check`:
 
 ```bash
 cp scripts/pre-commit .git/hooks/pre-commit
 chmod +x .git/hooks/pre-commit
 ```
 
-## Update
+### Running tests
 
 ```bash
-pip install --upgrade dapi
+pip install pytest
+pytest tests/ -v
+```
+
+### Linting
+
+```bash
+ruff format --check .
+ruff check .
+```
+
+To auto-fix lint errors:
+
+```bash
+ruff check --fix .
 ```