Sub-headers, move fork explanation text

README.md

@@ -236,6 +236,8 @@ it here.
 The `Makefile` will clone the repositories, install the Gem bundles and set up
 basic configuration files. Pick one:
+### Develop in a fork
+
 ```
 # Set up GDK with 'origin' pointing to your gitlab-ce fork.
 # Replace MY-FORK with your namespace
@@ -243,6 +245,19 @@ make gitlab_repo=https://gitlab.com/MY-FORK/gitlab-ce.git
 support/set-gitlab-upstream
 ```
+The set-gitlab-upstream script creates a remote named `upstream` for
+[the canonical GitLab CE
+repository](https://gitlab.com/gitlab-org/gitlab-ce). It also modifies
+`make update` (See [Update gitlab and gitlab-shell
+repositories](Update gitlab and gitlab-shell repositories)) to pull
+down from the upstream repository instead of your fork, making it
+easier to keep up-to-date with the project.
+
+If you want to push changes from upstream to your fork, run `make
+update` and then `git push origin` from the `gitlab` directory.
+
+### Develop in the main repo
+
 Alternatively, you can clone all components from their official source.
 ```
@@ -250,11 +265,6 @@ Alternatively, you can clone all components from their official source.
 make
 ```
-In order to more easily contribute changes back from a fork of the GitLab repository, you can run `support/set-gitlab-upstream` after `make` has finished. This creates a remote named `upstream` for [the canonical GitLab CE repository](https://gitlab.com/gitlab-org/gitlab-ce).
-
-This also modifies `make update` (See [Update gitlab and gitlab-shell repositories](Update gitlab and gitlab-shell repositories)) to pull down from the upstream repository instead of your fork, making it easier to keep up-to-date with the project.
-
-If you want to push changes from upstream to your fork, run `make update` and then `git push origin` from the `gitlab` directory.
 If you are going to work on Gitlab Geo, you will need [PostgreSQL replication](#postgresql-replication) setup before the "Post-installation" instructions.