Improved instructions on use database

Author: dfreniche

docs/30-simple-queries/0-using-library-database.mdx

@@ -2,7 +2,7 @@
 
 ## Select the library database
 
-We'll use the `library` database. To do that, in a MongoDB shell type in:
+💻 We'll use the `library` database. To do that, in a MongoDB shell type in:
 
 ```js
 use library
@@ -14,7 +14,11 @@ You can show all collections with
 show collections
 ```
 
-💻 How would you switch to a database called `orders`?
+🦸‍♂️ 💻 How would you switch to a database called `orders`?
+
+:::info
+Extra activity, do it if you have extra time or are following at home, won't be covered during the hands-on Lab
+:::
 
 <details>
 <summary>Answer</summary>
@@ -23,6 +27,14 @@ show collections
 ```js
 use orders
 ```
+
+Even if this database does not yet exists, MongoDB can change to it. If we create a collection, users, etc. then this DB will get created.
+
+Remember to get back to the library database by using:
+
+```js
+use library
+```
 </div>
 </details>