Set modules.

src/bootstrap/Alert.md

@@ -0,0 +1,20 @@
+Bootstrap alert component.
+```jsx
+import {useState} from 'react';
+
+function AlertExample(){
+    const [alert, setAlert] = useState(true);
+    if (alert)
+        return <Alert 
+            type='warning' 
+            message='Some warning out there!' 
+            onDismiss={()=>setAlert(false)}
+        />;
+    return <button 
+        className='btn btn-secondary' 
+        onClick={()=>setAlert(true)}
+    >Show alert again</button>;
+};
+<AlertExample/>
+
+```