Add manual-advance.md to the summary.

Author: CakeVR

documentation/SUMMARY.md

@@ -27,6 +27,7 @@
 - [Input]()
 
   - [Auto-Advance](auto-advance.md)
+  - [Manual-Advance](manual-advance.md)
   - [Auto-Skip](auto-skip.md)
 
 - [Utilities]()
@@ -134,4 +135,4 @@
     - [Util](classes/class_dialogicutil.md)
     - [VisualEditorField](classes/class_dialogicvisualeditorfield.md)
 
-[Contributing](contributing.md)
+[Contributing](contributing.md)