feat: Rework CONTRIBUTING.md (#413)

* feat: Rework CONTRIBUTING.md

* fix: typo

Author: Gu1nness

CONTRIBUTING.md

@@ -5,44 +5,18 @@
 This documents explains the processes and practices recommended for contributing enhancements to
 this operator.
 
-- Generally, before developing enhancements to this charm, you should consider [opening an issue
-  ](https://github.com/canonical/mongodb-k8s-operator/issues) explaining your use case.
-- If you would like to chat with us about your use-cases or proposed implementation, you can reach
-  us at [Canonical Mattermost public channel](https://chat.charmhub.io/charmhub/channels/charm-dev)
-  or [Discourse](https://discourse.charmhub.io/).
-- Familiarising yourself with the [Charmed Operator Framework](https://juju.is/docs/sdk) library
-  will help you a lot when working on new features or bug fixes.
-- All enhancements require review before being merged. Code review typically examines
+**Note:** The charm's python business logic is written in a shared library that can be found [here](https://github.com/canonical/mongo-single-kernel-library). This is where python contributions should be made.
+
+- Generally, before developing enhancements to this charm, you should consider opening an issue [on Single Kernel repository](https://github.com/canonical/mongo-single-kernel-library/issues) explaining your use case.
+- If you would like to chat with us about your use-cases or proposed implementation, you can reach us on our [Matrix channel](https://matrix.to/#/#charmhub-data-platform:ubuntu.com) or in [Discourse](https://discourse.charmhub.io/).
+- Familiarising yourself with the [Charmed Operator Framework](https://juju.is/docs/sdk) library will help you a lot when working on new features or bug fixes.
+- All enhancements require review before being merged. Additionally, new code must pass the tests. Code review typically examines
   - code quality
   - test coverage
-  - user experience for Juju administrators this charm.
-- Please help us out in ensuring easy to review branches by rebasing your pull request branch onto
-  the `main` branch. This also avoids merge commits and creates a linear Git commit history.
-
-## Prepare environment
-
-```shell
-# Juju
-sudo snap install juju --classic
-
-# charmcraft
-sudo snap install charmcraft --classic
-sudo usermod -a -G lxd $USER
-lxd init --auto
-lxc network set lxdbr0 ipv6.address none
-
-# microk8s
-sudo snap install microk8s --classic --channel=1.21
-sudo usermod -a -G microk8s $USER
-sudo chown -f -R $USER ~/.kube
-microk8s status --wait-ready
-
-# tox poetry
-sudo apt update
-sudo apt install -y pip
-python3.8 -m pip install tox poetry
-export PATH=$PATH:$HOME/.local/bin
-```
+  - user experience for Juju administrators of this charm.
+- Please help us out in ensuring easy to review branches by rebasing your pull request branch onto the `main` branch. This also avoids merge commits and creates a linear Git commit history.
+- Once the code has been merged on the [repository](https://github.com/canonical/mongo-single-kernel-library/) of the Mongo Single Kernel lib, wait for a new version of the [python package](https://pypi.org/project/mongo-charms-single-kernel/) to be published, and create a PR on this repository that bumps the version of the package, and on the 3 other repositories ([MongoDB VM](https://github.com/canonical/mongodb-operator), [Mongos VM](https://github.com/canonical/mongos-operator) and [Mongos k8s](https://github.com/canonical/mongos-k8s-operator)).
+- If you added some new interfaces, please don't forget to add them here.
 
 ### Testing
 
@@ -51,6 +25,7 @@ tox run -e fmt           # update your code according to linting rules
 tox run -e lint          # code style
 tox run -e unit          # unit tests
 tox run -e integration   # integration tests
+tox run -e integration -- 'tests/integration/test_charm.py' --group='1'   # charm integration tests
 tox                      # runs 'fmt', 'lint' and 'unit' environments
 ```
 
@@ -67,10 +42,12 @@ charmcraft pack
 ```bash
 # Create a model
 juju add-model dev
+
 # Enable DEBUG logging
 juju model-config logging-config="<root>=INFO;unit=DEBUG"
+
 # Deploy the charm
-juju deploy ./mongodb-k8s_ubuntu-22.04-amd64.charm --resource mongodb-image=dataplatformoci/mongodb:5.0 --num-units=1
+juju deploy ./mongodb-k8s_ubuntu-22.04-amd64.charm --resource mongodb-image=ghcr.io/canonical/charmed-mongodb@sha256:7ddb80a3b5ddffa95704a8980fc11037ba1a23273a9805214bc42be9f507107f --num-units=1
 ```
 
 ## Canonical Contributor Agreement