message: Document JSON compatibility guarantees.
diff: @@ -426,6 +426,8 @@ it, this will provide you an easy way to use that data directly.
  (see the schema documentation for some specifics on the JSON format
  accepted).
  +Schema evolution compatibility for the JSON format follows the same rules as the binary format (JSON formatted data will be forwards/backwards compatible with schemas that evolve in a compatible way).
  +
  There are two ways to use text formats:
  #### Using the compiler as a conversion tool
  