Add Grafbase to list of services (#1374)

Author: mlafeldt

src/content/code/services/grafbase.md

@@ -0,0 +1,5 @@
+---
+name: Grafbase
+description: GraphQL backends made easy. Build your backend declaratively using a schema-first approach. Accelerate development and reduce boilerplate code by leveraging powerful directives and scalars.
+url: https://grafbase.com
+---