Add grpcmd to Showcase (#2181)

Co-authored-by: Chris Swithinbank <[email protected]>

Author: AkshayKalose

docs/src/assets/showcase/grpc.md.png

@@ -157,4 +157,5 @@ import FluidGrid from './fluid-grid.astro';
 		thumbnail="styledictionary.com.png"
 	/>
 	<Card title="CodeSweetly" href="https://codesweetly.com/" thumbnail="codesweetly.com.png" />
+	<Card title="grpcmd" href="https://grpc.md/" thumbnail="grpc.md.png" />
 </FluidGrid>