emphasize the use of "git status"; closes #451

Author: bast

content/commits.md

@@ -452,3 +452,5 @@ their differences.
   files with sensitive information or files which are generated as part of
   the build process should not be added to Git. For this we use
   `.gitignore` (more about this later: {ref}`what-to-avoid`).
+- Unsure on which branch you are or what state the repository is in?
+  On the command line, use `git status` frequently to get a quick overview.

content/level.md

@@ -1,10 +1,19 @@
-# Practical advice: how much Git is necessary?
+# Practical advice: How much Git is necessary?
 
 :::{instructor-note}
 - 20 min teaching/discussion
 :::
 
 
+## Working on the command line? Use "git status" all the time
+
+Unsure on which branch you are or what state the repository is in?  On the
+command line, use `git status` frequently to get a quick overview.
+The `git status` command is one of the most useful commands in Git
+to inform about which branch we are on, what we are about to commit,
+which files might not be tracked, etc.
+
+
 ## Writing useful commit messages
 
 Useful commit messages summarize the change and provide context.