Merge ~clinton-fung/launchpad:doc-howto-contributing-changes into launchpad:master

[Clinton Fung]

Added new How-to for contributing changes to Launchpad (action from Launchpad team retro 2022/08/10)

Added new How-to for contributing changes to Launchpad (action from Launchpad team retro 2022/08/10)

[Guruprasad (lgp171188)]

I left some comments and suggestions.

[Guruprasad (lgp171188)]

LGTM 👍

review: Approve

[Colin Watson (cjwatson)]

review: Approve

diff --git a/doc/how-to/contributing-changes.rst b/doc/how-to/contributing-changes.rst
new file mode 100644
index 0000000..0ab219e
--- /dev/null
+++ b/doc/how-to/contributing-changes.rst
@@ -0,0 +1,62 @@
+====================
+Contributing changes
+====================
+
+This guide shows you how to contribute a change to Launchpad.
+
+Discuss the change
+------------------
+
+To begin with, it is usually helpful to discuss the change you'd like to make, in a `bug <https://bugs.launchpad.net/launchpad>`_, in the `launchpad-users <https://launchpad.net/~launchpad-users>`_ or `launchpad-dev <https://launchpad.net/~launchpad-dev>`_ mailing lists, or on IRC (``#launchpad-dev`` on ``irc.libera.chat``).
+
+Get the Launchpad source
+----------------------------
+
+Once you have decided on the change to be made, clone the repository.
+
+.. code-block:: bash
+
+    git clone https://git.launchpad.net/launchpad
+
+Make your changes
+-------------------
+
+Create a branch from a reasonable point, such as ``master``.
+
+.. code-block:: bash
+
+    git checkout -b my-change
+
+Make your changes on the branch. Be sure to test them locally (by setting up a local `Launchpad development instance <https://launchpad.readthedocs.io/en/latest/how-to/running.html>`_)!
+
+Run the pre-commit hook
+-----------------------
+
+If you followed the instructions to `set up and run Launchpad <https://launchpad.readthedocs.io/en/latest/how-to/running.html#>`_, you should already have ``pre-commit`` installed and have the ``pre-commit`` git hook `installed <https://launchpad.readthedocs.io/en/latest/how-to/running.html#installing-the-pre-commit-hook>`_. If not, complete these steps before proceeding.
+
+Push your changes
+--------------------
+
+Once you are happy with your changes, stage and commit them, and then push to a personal repository.
+
+Next, you need to share your changes with the Launchpad maintainers, but you probably don't have permissions to push to the ``master`` branch of the Launchpad codebase. To share your changes with the Launchpad maintainers, you need to push your commit to a personal git repository.
+
+Create a merge proposal
+-----------------------
+
+Once your commit has been pushed to a personal git repository, you can follow the direct link in the post-push message to create a merge proposal. Alternatively, in a web browser, visit 
+
+.. code-block:: bash
+
+    https://code.launchpad.net/~<username>/+git
+
+Remember to replace your username in the URL.
+
+Navigate to the personal repository to which you pushed your changes, and then to the branch containing your commit.
+
+Select Propose for merging, provide a reasonable commit message, and description of your changes.
+
+What comes next?
+----------------
+
+Once you have created a merge proposal, a Launchpad maintainer will inspect your commit and approve or reject the changes. There may be a comments that require you to make amendments to your proposed changes, which you can do by repeating this workflow. However, once your changes are approved, your changes will be merged into the ``master`` branch of the Launchpad code base!
diff --git a/doc/how-to/index.rst b/doc/how-to/index.rst
index 7fae5e5..3222260 100644
--- a/doc/how-to/index.rst
+++ b/doc/how-to/index.rst
@@ -17,6 +17,7 @@ Common development tasks
 .. toctree::
    :maxdepth: 1
 
+   contributing-changes
    exceptions
    security
    avoid-debugging-issues