Add deployment pipeline

Author: woojiahao

docs/architecture/deployment-pipeline.md

@@ -3,3 +3,23 @@ title: Deployment Pipeline
 parent: Architecture
 nav_order: 5
 ---
+
+## Exercises
+
+Unit tests and [exercise configuration](/developers/docs/architecture/exercise-structure/#configuration-structure) will be run during the PR and every time a branch is merged into `main`.
+
+These are controlled through the `CI` action on Github Actions ([here](https://github.com/git-mastery/exercises/actions/workflows/ci.yml)).
+
+## Git-Mastery app
+
+A new version of the Git-Mastery application is published when a new tag is pushed to `main`.
+
+The versioning is done as follows: `<major>.<minor>.<patch>` where
+
+1. `<major>`: for when major changes to the app occur (i.e. rewrites) where the application could break entirely
+2. `<minor>`: for when critical bug fixes occur that users should be aware of
+3. `<patch>`: for when minor bug fixes occur (i.e. cosmetic) that users don't need to update to
+
+The app automatically checks for the latest version published and warns users if their local version is out of date if the `<major>` or `<minor>` versions are wrong.
+
+If you do not have permissions to push a new tag, contact <woojiahao1234@gmail.com> for assistance.