fix: importing parseValue helper

For some reason forget to export 'parseValue' function in the index.ts.

Resolves #34

src/index.ts

@@ -1,3 +1,3 @@
 export * from './components';
 export { Suggestion, MentionSuggestionsProps } from './types';
-export { mentionRegEx, replaceMentionValues, getMentionValue } from './utils';
+export { mentionRegEx, parseValue, replaceMentionValues, getMentionValue } from './utils';