* adding effectiveDate frontmatter property * Update components/article/ArticlePage.tsx Co-authored-by: Peter Bengtsson <peterbe@github.com> * adding validation for correct date * update to dateTime * update to year month day * update error date validation * moving validation to getArticleContextFromRequest and moving id to div * remove enteredDate * Update content/README.md Co-authored-by: Laura Coursen <lecoursen@github.com> Co-authored-by: Peter Bengtsson <peterbe@github.com> Co-authored-by: Laura Coursen <lecoursen@github.com>