Merge pull request #924 from cucumber/gherkin-dialect-export

gherkin/javascript: make Dialect available on main export

gherkin/javascript/src/index.ts

@@ -1,6 +1,7 @@
 import Gherkin from './Gherkin'
 import IGherkinOptions from './IGherkinOptions'
 import Query from './Query'
+import Dialect from './Dialect'
 
 export default Gherkin
-export { IGherkinOptions, Query }
+export { IGherkinOptions, Query, Dialect }