Update markdown.md

Author: staeiou

_pages/markdown.md

@@ -7,7 +7,7 @@ redirect_from:
   - /markdown.html
 ---
 
-## Jekyll / theme guide
+## Locations of key files/directories
 
 * Basic config options: _config.yml
 * Top navigation bar config: _data/navigation.yml
@@ -18,6 +18,9 @@ redirect_from:
   * _posts/
   * _teaching/
   * _talks/
+* Footer: _includes/footer.html
+* Static files (like PDFs): /files/
+* Profile image (can set in _config.yml): images/profile.png
 
 ## Tips and hints