Use instructor-note directive where appropriate

contributing.md

@@ -18,15 +18,6 @@ belong to others.
 We will do this in a progression from a small trivial fix to a change proposal
 and discuss the pros and cons.
 
-
-## Note to instructors
-
-- The instructor will prepare an example repository and share the link with the
-  participants (see instructor guide for more details).
-- This is a good example text: <https://www.gutenberg.org/ebooks/24542>
-- When showing how to add a collaborator, also show how to unwatch a repo.
-
-
 > ## Recap: different methods to "download" a repository
 >
 > - There is no need to download each file one by one.
@@ -37,6 +28,14 @@ and discuss the pros and cons.
 > - Cloning copies not only the latest version but all snapshots and all branches and tags: entire history.
 {: .discussion}
 
+```{instructor-note}
+- The instructor will prepare an example repository and share the link with the
+  participants (see instructor guide for more details).
+- This is a good example text: <https://www.gutenberg.org/ebooks/24542>
+- When showing how to add a collaborator, also show how to unwatch a repo.
+```
+
+
 ---
 
 ## Step 1: Learn how to add collaborators to your repository
@@ -135,12 +134,11 @@ sharing screen:
 
 ## Step 4: Resolving a conflict
 
-### Note to instructors
-
+```{instructor-note}
 - "Non-talking instructor" prepares a conflicting commit during session (check
   what the first PR does).
 - Conflict can be shown as demo.
-
+```
 
 ### Exercise/demo: let us experience a conflict
 

creating-using-web.md

@@ -24,11 +24,12 @@ suggestions. In a larger group the instructor can demonstrate these and then
 participants can try on their own and then ask questions.
 
 
-## Note to instructors
 
+```{instructor-note}
 In this episode we are all in the main room and do these steps together as
 follow-along with pauses with time for questions and answers, no breakout rooms
 yet.
+```
 
 ---
 

group-work.md

@@ -76,12 +76,11 @@ Should I add everybody as collaborator?
 
 ## Optional exercise contributing larger changes
 
-### Note to instructors
-
+```{instructor-note}
 - A participant shares screen and creates a repository, then instructor takes screen share and
   we go through steps to contribute to that repository (without write permissions), then
   screen share goes back to participant and we together review this change
-
+```
 
 ### Exercise