Add jsxFragmentFactory option for TS 4.0 (#1117)

Author: weswigham

src/schemas/json/tsconfig.json

@@ -530,6 +530,11 @@
               "type": "string",
               "default": "React.createElement"
             },
+            "jsxFragmentFactory": {
+              "description": "Specify the JSX Fragment reference to use for fragements when targeting react JSX emit, e.g. 'React.Fragment' or 'Fragment'. Requires TypeScript version 4.0 or later.",
+              "type": "string",
+              "default": "React.Fragment"
+            },
             "alwaysStrict": {
               "description": "Parse in strict mode and emit 'use strict' for each source file. Requires TypeScript version 2.1 or later.",
               "type": "boolean"