message: Add availability note to resolver option
diff: @@ -249,6 +249,8 @@ If enabled, the module registry for every test file will be reset before running
  ### `resolver` [string]
  Default: `undefined`
  +##### available in Jest **20.0.0+**
  +
  This option allows the use of a custom resolver. This resolver must be a node module that exports a function expecting a string as the first argument for the path to resolve and an object with the following structure as the second argument:
  ```
  