Remove unnecessary line 

**Steps to Reproduce** 
1. Go to https://moja-global.github.io/Handbook/Chapter5/section_two.html
2. Read  the Prerequisite section 

 Remove  `## GCBM Installation Guide ` 

![Screenshot from 2023-01-31 20-39-49](https://user-images.githubusercontent.com/92504666/215834613-f537ebee-a748-4777-9b0c-8941a119f748.png)