fixing typo

Author: sushilshinde

src/shared/components/challenge-detail/Specification/SideBar/index.jsx

@@ -355,5 +355,5 @@ SideBar.propTypes = {
   isDevelop: PT.bool,
   environment: PT.string,
   codeRepo: PT.string,
-  isMM:PR.bool,
+  isMM:PT.bool,
 };