Add support for nav_order and Fix hardcoded navbar titles (alshediv…

…at#664)

_pages/teaching.md

@@ -4,6 +4,7 @@ permalink: /teaching/
 title: teaching
 description: Materials for courses you taught. Replace this text with your description.
 nav: true
+nav_order: 2
 ---
 
 For now, this page is assumed to be a static description of your courses. You can convert it to a collection similar to `_projects/` so that you can have a dedicated page for each course.