update contributing to packages to not mention amp develop

docs/contributing-to-packages.md

@@ -9,22 +9,27 @@ in the proper package's repository.
 
 ### Cloning
 
-The first step is creating your own clone. You can of course do this manually
-with git, or you can use the `apm develop` command to create a clone based on
-the package's `repository` field in the `package.json`.
+The first step is creating your own clone.
 
-For example, if you want to make changes to the `tree-view` package, run the
-following command:
+For example, if you want to make changes to the `tree-view` package, fork the repo on your github account, then clone it:
 
 ```
-> apm develop tree-view
-Cloning https://github.com/atom/tree-view ✓
+> git clone git@github.com:your-username/tree-view.git
+```
+
+Next install all the dependencies:
+
+```
+> cd tree-view
+> apm install
 Installing modules ✓
-~/.atom/dev/packages/tree-view -> ~/github/tree-view
 ```
 
-This clones the `tree-view` repository to `~/github`. If you prefer a different
-path, specify it via the `ATOM_REPOS_HOME` environment variable.
+Now you can link it to development mode so when you run an Atom window with `atom --dev`, you will use your fork instead of the built in package:
+
+```
+> apm link -d
+```
 
 ### Running in Development Mode
 
@@ -46,7 +51,4 @@ from the package directory to create and remove dev-mode symlinks.
 
 ### Installing Dependencies
 
-Finally, you need to install the cloned package's dependencies by running
-`apm install` within the package directory. This step is also performed
-automatically the first time you run `apm develop`, but you'll want to keep
-dependencies up to date by running `apm update` after pulling upstream changes.
+You'll want to keep dependencies up to date by running `apm update` after pulling any upstream changes.