Some grammar fixes

(lower case after  period, and also reiteration at the beginning)

README.md

@@ -45,8 +45,7 @@ You should also specify settings that will be shared across all the plugin rules
       "fragment": "Fragment",  // Fragment to use (may be a property of <pragma>), default to "Fragment"
       "version": "detect", // React version. "detect" automatically picks the version you have installed.
                            // You can also use `16.0`, `16.3`, etc, if you want to override the detected value.
-                           // default to latest and warns if missing
-                           // It will default to "detect" in the future
+                           // It will default to "latest" and warn if missing, and to "detect" in the future
       "flowVersion": "0.53" // Flow version
     },
     "propWrapperFunctions": [