chore(types): add additional hint for LSP support (#864)

Signed-off-by: Aaron <29749331+aarnphm@users.noreply.github.com>

quartz/components/Header.tsx

@@ -1,6 +1,6 @@
-import { QuartzComponentConstructor, QuartzComponentProps } from "./types"
+import { QuartzComponent, QuartzComponentConstructor, QuartzComponentProps } from "./types"
 
-function Header({ children }: QuartzComponentProps) {
+const Header: QuartzComponent = ({ children }: QuartzComponentProps) => {
   return children.length > 0 ? <header>{children}</header> : null
 }