Minor README updates

Author: cretz

README.md

@@ -1,28 +1,38 @@
 # Temporal Python SDK
 
-### Local development enviroment
+**UNDER DEVELOPMENT**
 
-- Install the system dependencies
+The Python SDK is under development. There are no compatibility guarantees nor proper documentation pages at this time.
+
+### Local development environment
+
+- Install the system dependencies:
 
   - Python >=3.7
-  - [pipx](https://github.com/pypa/pipx#install-pipx)
-  - [`poetry`](https://github.com/python-poetry/poetry) `pipx install poetry`
-  - [`poe`](https://github.com/nat-n/poethepoet) `pipx install poethepoet`
+  - [pipx](https://github.com/pypa/pipx#install-pipx) (only needed for installing the two dependencies below)
+  - [poetry](https://github.com/python-poetry/poetry) `pipx install poetry`
+  - [poe](https://github.com/nat-n/poethepoet) `pipx install poethepoet`
 
 - Use a local virtual env environment (helps IDEs and Windows):
 
   ```bash
   poetry config virtualenvs.in-project true
   ```
 
-- Install the package dependencies
+- Install the package dependencies:
 
   ```bash
   poetry install
   ```
 
-- Build the project
+- Build the project:
 
   ```bash
   poe build
   ```
+
+- Run the tests:
+
+  ```bash
+  poe test
+  ```