Update page.mdx (#6302)

Signed-off-by: Waren Gonzaga <github@warengonzaga.com>

Author: warengonzaga

apps/portal/src/app/contracts/modular-contracts/overview/page.mdx

@@ -72,4 +72,4 @@ and swap them out to enable different functionality.
 </div>
 
 ### Templates
-[Extenion Starter Template](https://github.com/thirdweb-example/modular-contract-starter)
+[Extension Starter Template](https://github.com/thirdweb-example/modular-contract-starter)