Add instructions on how to update when forking our repository

- Add some examples commands for git on how to update with latest changes from upstream.

Author: sondreb

Documentation/forking.md

@@ -0,0 +1,27 @@
+# Forking
+
+To fork this repo, and continue to get patches and updates, you need to make sure you fetch updates correctly from the upstream repo.
+
+```
+# Fetch the changes from upstream repo
+git fetch upstream
+
+# View all branches
+git branch -va
+```
+
+Depending of you are working with master as the primary branch or not, you can do the following to checkout your branch, and then
+perform an merge with upstream branch.
+
+```
+git checkout master
+git merge upstream/master
+```
+
+## Resources
+
+[GitHub Standard Fork & Pull Request Workflow](https://gist.github.com/Chaser324/ce0505fbed06b947d962)
+
+[Merging an upstream repository into your fork](https://help.github.com/articles/merging-an-upstream-repository-into-your-fork/)
+
+[Long-Running Branches](https://github.com/dotnet/llilc/blob/master/Documentation/Long-Running-Branch-Workflow.md)