refactor: Remove old react lifecycle methods (#1480)

* refactor: Remove deprecated APIs

* bump mobx-react for hooks support

* inject -> useStores
https://mobx-react.js.org/recipes-migration\#hooks-to-the-rescue

* chore: React rules of hooks lint

app/components/HoverPreview.js

@@ -20,12 +20,7 @@ type Props = {
   onClose: () => void,
 };
 
-function HoverPreview({ node, documents, onClose, event }: Props) {
-  // previews only work for internal doc links for now
-  if (!isInternalUrl(node.href)) {
-    return null;
-  }
-
+function HoverPreviewInternal({ node, documents, onClose, event }: Props) {
   const slug = parseDocumentSlugFromUrl(node.href);
 
   const [isVisible, setVisible] = React.useState(false);
@@ -131,6 +126,15 @@ function HoverPreview({ node, documents, onClose, event }: Props) {
   );
 }
 
+function HoverPreview({ node, ...rest }: Props) {
+  // previews only work for internal doc links for now
+  if (!isInternalUrl(node.href)) {
+    return null;
+  }
+
+  return <HoverPreviewInternal {...rest} node={node} />;
+}
+
 const Animate = styled.div`
   animation: ${fadeAndSlideIn} 150ms ease;