chore(docs): fix e-commerce showcase link (#23053)

Access the page in question: https://www.gatsbyjs.org/docs/building-an-e-commerce-site/

docs/docs/building-an-e-commerce-site.md

@@ -4,7 +4,7 @@ title: Building an E-commerce Site
 
 The speed and performance of sites built with Gatsby make it a great tool for building e-commerce sites. There are existing plugins for connecting services like [Shopify](/packages/gatsby-source-shopify/) and [Snipcart](/packages/gatsby-plugin-snipcart/) to Gatsby, and this section contains reference guides to help get things setup.
 
-To see examples of e-commerce sites built with Gatsby, check out the [showcase](/showcase/?filters%5B0%5D=eCommerce).
+To see examples of e-commerce sites built with Gatsby, check out the [showcase](/showcase/?filters%5B0%5D=E-commerce).
 
 <GuideList slug={props.slug} />