feat: add remark widont extension

Idea from this article: https://eatmon.co/blog/remove-runts-markdown/

src/utils/index.ts

@@ -2,6 +2,7 @@ export * from './date';
 export * from './format-posts';
 export * from './pick-two-random-colors';
 export * from './remark-reading-time';
+export * from './remark-widont';
 export * from './sort-by-alphabet';
 export * from './sort-by-date';
 export * from './sort-by-sortkey';