Specialised contribution instructions for dev

Author: leriomaggio

CONTRIBUTING.md

@@ -1,5 +1,45 @@
 # Contribution guide for developers
 
+## Development
+
+### Setting up the environment
+
+To get started, you will need to setup the development environment. This goes
+through two main steps, namely [(1) Installing `pyscript-cli` dependencies](#install-pyscript-cli-dependencies)
+and [(2) Installing `pyscript-cli` Dev dependencies](#install-the-development-dependencies).
+
+### Install `pyscript-cli` dependencies
+
+`pyscript-cli` requires [`poetry`](https://python-poetry.org/) to manage dependencies
+and setup the environment.
+
+Therefore, the first thing to do is to make sure that you have `poetry` installed
+in your current Python environment. Please refer to the official `poetry`
+[documentation](https://python-poetry.org/docs/master/#installation) for installation
+instructions.
+
+To install `pyscript-cli` dependencies, you will need to run the following command from the project root:
+
+```shell
+poetry install
+```
+
+### Install the development dependencies
+
+There are a few extra dependencies that are solely required for development.
+To install these packages, you will need to run the following command from the project root:
+
+```shell
+poetry install --with dev-dependencies
+```
+
+Once all the dependencies are installed, you will only need to setup the git hooks
+via [`pre-commit`](https://pre-commit.com/):
+
+```shell
+pre-commit install
+```
+
 ## Documentation
 
 ### Install the documentation dependencies