move command line git merge to 4.1

Author: rogerkuou

episodes/41-code-review.md

@@ -567,6 +567,27 @@ This tells the author you are happy for them to merge the pull request.
   ![](fig/github-merge-pull-request.png){alt='Merging a pull request in GitHub' .image-with-shadow width="800px"}
 2. Delete the merged branch to reduce the clutter in the repository.
 
+::: callout
+
+### Merge via command line
+
+The `git merge` command provides a way to directly merge branches on your local. In general, when adding changes to the `main` branch, this is not a good practice since it bypasses the code review process. It is a common practice for an open-source project to set its `main` branch protected, meaning pushing directly to `main` branch will fail. Therefore, even you can merge to `main` locally, you will not be able to push the changes to the remote repository.
+
+On the other hand, the `git merge` command can be very useful for keeping your feature branch up to date with the `main` branch. For example, if you are working on a branch `my-feature` and the `main` branch has received new commits (e.g. someone else has merged their pull request), you can do the following to include changes from `main` into your feature branch:
+
+```bash
+# First update your local main branch 
+$ git checkout main
+$ git pull main
+# Then switch back to your feature branch and merge the latest main into it
+$ git checkout my-feature
+$ git merge main
+```
+
+In this way, you can keep your feature branch up to date. You may need to resolve conflicts that arise during this process.
+
+:::
+
 ## Writing Easy-To-Review Code
 
 There are a few things you can do to make it

episodes/42-software-reuse.md

@@ -344,30 +344,6 @@ Ensure you prioritise and work on the most pressing issues first!
 
 ::::::::::::::::::::::::::::::::::::::::::::::::::
 
-## Merging into `main`
-
-Once you have done these updates,
-commit your changes,
-and if you are doing this work on a feature branch also ensure you merge it into `develop`,
-e.g.:
-
-```bash
-$ git switch develop
-$ git merge my-feature-branch
-```
-
-Finally, once we have fully tested our software
-and are confident it works as expected on `develop`,
-we can merge our `develop` branch into `main`:
-
-```bash
-$ git switch main
-$ git merge develop
-$ git push origin main
-```
-
-The software on your `main` branch is now ready for release.
-
 ## Tagging a Release in GitHub
 
 There are many ways in which Git and GitHub can help us make a software release from our code.