Add doc comment.

Author: taeold

src/gcp/frameworks.ts

@@ -19,6 +19,12 @@ interface Codebase {
   rootDirectory: string;
 }
 
+/**
+ * Specifies how Backend's data is replicated and served.
+ *   GLOBAL_ACCESS: Stores and serves content from multiple points-of-presence (POP)
+ *   REGIONAL_STRICT: Restricts data and serving infrastructure in Backend's region
+ *
+ */
 export type ServingLocality = "GLOBAL_ACCESS" | "REGIONAL_STRICT";
 
 /** A Backend, the primary resource of Frameworks. */