correct large size hours

Author: TimidRobot

content/programs/lead-guide/contents.lr

@@ -52,7 +52,7 @@ _**[Project Title]**_
 - **Technical Skills**: _What technical skills will this project need?_
 - **Difficulty**: _How technically difficult is this project? Options: High,
   Medium, Low_
-- **Size**: _Large (~305 hours) or Medium (~175 hours)._
+- **Size**: _Large (~350 hours) or Medium (~175 hours)._
 
 Please note that project ideas should be related to an existing CC open source
 project or website and should be clearly scoped out. They should be doable in