docs(pgai): improve the development docs for the pgai library (#493)

projects/pgai/DEVELOPMENT.md

@@ -1,10 +1,65 @@
 ## Working on the pgai library
 
+
+Note: We try to somewhat follow the python release schedule for supported versions to allow more users to use our library.
+Therefore, we are about a year behind the latest python release.
+
+### Set up your environment
+
 The experience of working on the pgai library is like developing most Python
 libraries and applications. We use [uv](https://docs.astral.sh/uv/getting-started/installation/) to manage dependencies and python versions. Once you have uv installed it's easy to get started.
 
-Note: We try to somewhat follow the python release schedule for supported versions to allow more users to use our library.
-Therefore we are about a year behind the latest python release.
+Make sure your uv version is at least `0.5.x`.
+
+```bash
+uv --version
+```
+
+If not, upgrade it with this command.
+
+```bash
+uv self update
+```
+
+Change directory into the [projects/pgai](/projects/pgai) directory and create a
+virtual environment. Then, activate it.
+
+```bash
+cd projects/pgai
+uv venv
+source .venv/bin/activate
+```
+
+Install the project's dependencies into the virtual environment.
+
+```bash
+uv sync --all-extras
+```
+
+The vectorizer worker and some tests use environment variables and can make use
+of a `.env` file. Creating one may make your life easier. Include the variables 
+below as you see fit.
+
+```text
+OLLAMA_HOST=""
+OPENAI_API_KEY=""
+VOYAGE_API_KEY=""
+MISTRAL_API_KEY=""
+COHERE_API_KEY=""
+HUGGINGFACE_API_KEY=""
+AZURE_OPENAI_API_KEY=""
+AZURE_OPENAI_API_BASE=""
+AZURE_OPENAI_API_VERSION=""
+ENABLE_VECTORIZER_TOOL_TESTS=1
+```
+
+Run the tests to verify you have a working environment.
+
+```bash
+just test
+```
+
+### Manage Python Dependencies
 
 Uv syncs the dependencies of all developers working on the project via the uv.lock file. If you want to add a new dependency make use of the uv add command:
 
@@ -18,14 +73,19 @@ If it is a development dependency and not needed at runtime, you can add the --d
 uv add --directory projects/pgai --dev <package-name>
 ```
 
-Uv installs all dependencies inside a virtual environment by default you can either activate this via the `uv shell` command or run commands directly via `uv run`.
+### Working with the project
 
-For the most common commands use the just recipes.
+We use [just](https://just.systems/man/en/) to define and run commands to work
+with the project. These include tasks like building, installation, linting, 
+and running tests. To see a list of the available commands, run the following 
+from the root of the repo:
 
 ```bash
 just -l pgai
 ```
 
+### Testing the pgai library
+
 Be sure to add unit tests to the [tests](./projects/pgai/tests) directory when
 you add or modify code. Use the following commands to check your work before
 submitting a PR.