PrettyError: redesign to make more reusable.

src/components/ErrorBoundary.tsx

@@ -59,7 +59,10 @@ class ErrorBoundary extends React.Component<PropsType> {
 
     if (error) {
       return (
+        <div>
+          <h2>Something went wrong!</h2>
           <PrettyError error={this.state.error} />
+        </div>
       );
     }
     return this.props.children;

src/widgets/PrettyError.tsx

@@ -2,12 +2,10 @@ import * as React from 'react';
 
 export const PrettyError = React.memo((props: any) => (
   <div>
-    <h2>Something went wrong!</h2>
+    <pre style={{ fontWeight: 'bold' }}>
-    <pre>
       {props.error.message}
     </pre>
 
-    <h3>Stack trace:</h3>
     <pre>
       {props.error.stack}
     </pre>