update essential commands

2021/2021-03-18_basicGitTraining/slides/essential_commands.md

@@ -31,14 +31,12 @@ Verify its `status` with:
 $ git status
 ```
 
-
-
 # Modify a file
 
-Copy the file `template.md` in the folder `attendees` and rename it with your firstname:
+Copy the file `firstnameLastname.md` in the folder `_attendees` and rename it with your firstname:
 
 ```bash
-$ cd attendees
+$ cd _attendees
 $ cp firstnameLastname.md myName.md
 ```