(docs) Add insomnia to Services section

Author: setchy

src/content/code/services/insomnia.md

@@ -0,0 +1,6 @@
+---
+name: Insomnia
+description: Insomnia is an open-source, cross-platform API Client for GraphQL, REST, and gRPC. Insomnia combines an easy-to-use interface with advanced functionality like authentication helpers, code generation, and environment variables.
+url: https://docs.insomnia.rest/insomnia/graphql-queries
+github: Kong/insomnia
+---