Improve Contributing documentation (#43)

CONTRIBUTING.md

@@ -1,17 +1,47 @@
 # Contributing
+To make contributions to this charm, you'll need a working Juju development setup.
 
-To make contributions to this charm, you'll need a working [Juju development setup](https://juju.is/docs/sdk/dev-setup).
+## Prerequisites
+Install Charmcraft and LXD:
+```shell
+sudo snap install --classic charmcraft
+sudo snap install lxd
+sudo adduser $USER lxd
+newgrp lxd
+lxd init --auto
+```
+
+Install MicroK8s:
+```shell
+sudo snap install microk8s --channel=1.27-strict/stable
+sudo usermod -a -G snap_microk8s $USER
+newgrp snap_microk8s
+sudo microk8s enable hostpath-storage
+```
 
-You can use the environments created by `tox` for development:
+Install Juju and bootstrap a controller on the MicroK8S instance:
+```shell
+sudo snap install juju --channel=3.1/stable
+juju bootstrap microk8s
+```
+
+Install `pip` and `tox`:
+```shell
+sudo apt install python3-pip
+python3 -m pip install "tox>=4.0.0"
+```
 
+## Development
+Activate the virtual environment created by `tox` for development:
 ```shell
 tox --notest -e unit
 source .tox/unit/bin/activate
 ```
 
 ## Testing
+This project uses `tox` for managing test environments.
 
-This project uses `tox` for managing test environments. There are some pre-configured environments
+There are some pre-configured environments
 that can be used for linting and formatting code when you're preparing contributions to the charm:
 
 ```shell
@@ -22,21 +52,7 @@ tox -e integration   # integration tests
 ```
 
 ## Build
-
-Building charms is done using charmcraft (official documentation [here](https://juju.is/docs/sdk/publishing)). You can install charmcraft using `snap`:
-
-```bash
-sudo snap install charmcraft --channel=classic
-```
-
-Initialize LXD:
-
-```bash
-lxd init --auto
-```
-
 Go to the charm directory and run:
-
 ```bash
 charmcraft pack
 ```