Update src/pages/gsoc_ideas.mdx

Co-authored-by: Chris Black <chris@ckblack.org>

Author: mdietze

src/pages/gsoc_ideas.mdx

@@ -14,7 +14,8 @@ Below is a list of project ideas. Feel free to contact the listed mentors on Sla
 
 1. [Refactor and Parallelize Input Processing Pipelines](#input)  
 2. [Benchmarking and Validation Framework](#validation)  
-3. [Increase PEcAn modularity](#module)   
+3. [Increase PEcAn modularity](#module)
+4. [Standardizing Model Couplers Across Models](#couplertools)
 
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