Update git-101.md

Add info about sync scenario [skip ci]

docs/git-101.md

@@ -44,3 +44,35 @@ changes, and issue a pull request.
 
 [Githug](https://github.com/Gazler/githug) is a great gamefied way to learn git in couple hours.
 After finishing 50+ real-world scenarios you will have a pretty good idea about what and when you can do with git.
+
+
+## Scenarios
+
+#### Sync your local repo
+
+Don't commit your changes directly to master.
+It would make workflow messy.
+
+Always create a branch for your changes.
+
+```sh
+# switch to master branch
+
+# fetch updates all remote branch references in the repo and all submodules
+# --all : tells it to do it for all remotes (handy, when you use your fork)
+# -p : tells it to remove obsolete remote branch references (when they are removed from remote)
+git fetch --all -p
+
+# pull updates your local files
+# you should call this command ONLY from master branch
+git pull origin master
+
+# update submodules
+git submodule update --recursive 
+```
+
+Then switch to your branch and do rebase
+
+```
+git rebase master
+```