In the Teacher Documentation topic, click on Add an activity... and select Wiki from the list.
The name of my new wiki is going to be Backyard Ballistics Guidelines. Enter a name for your wiki.
Write a brief summary of the wiki. This is shown above every page. Keep it short and descriptive.
Click on the Type option and select Teacher from the list. This means that students can only view the wiki (but remember that we have hidden the topic that it's in):
5. Scroll to the bottom of the page and press the Save and return to course button.