feat: sub-title component 구현

Author: SimDaSong

components/sub-title/index.tsx

@@ -0,0 +1,17 @@
+import React from "react";
+
+type Props = {
+  children: string;
+};
+
+const classes = {
+  subTitle: "text-2xl font-bold text-gray-900",
+};
+
+const SubTitle = (props: Props) => {
+  const { children } = props;
+
+  return <p className={classes.subTitle}>{children}</p>;
+};
+
+export default SubTitle;