fix title location of lp_intro (#333)

Author: HumphreyYang

lectures/lp_intro.md

@@ -10,6 +10,7 @@ kernelspec:
 ---
 
 (lp_intro)=
+# Linear Programming
 
 In this lecture, we will need the following library. Install [ortools](https://developers.google.com/optimization) using `pip`.
 
@@ -20,8 +21,6 @@ tags: [hide-output]
 !pip install ortools
 ```
 
-# Linear Programming
-
 ## Overview
 
 **Linear programming** problems either maximize or minimize