Set modules.

src/bootstrap/Modal.md

@@ -0,0 +1,27 @@
+Bootstrap modal component.
+
+I have no idea why example doesn't work here but you can investigate HTML code...
+```js
+import {ModalHeader, ModalBody, ModalFooter} from './Modal';
+
+import {useState} from 'react';
+const [shown, setShown] = useState(false);
+
+<>
+    <Modal shown={shown}>
+        <ModalHeader setShown={setShown} title='Warning!'/>
+        <ModalBody><p>Bla bla bla...</p></ModalBody>
+        <ModalFooter>
+            <button 
+                className='btn btn-secondary' 
+                onClick={() => setShown(false)}
+            >Skip it</button>
+        </ModalFooter>
+    </Modal>
+    
+    <button 
+        className='btn btn-secondary'
+        onClick={()=>setShown(true)}
+    >Show modal</button>
+</>
+```