Review code examples to ensure they work with the new Stackblitz functionality

[GCHQ-Developer-112]

Summary

Following the introduction of the Stackblitz functionality, a review is needed of the code examples. This review will focus on ensuring that code examples display correctly in Stackblitz when the "Open in Stackblitz" button is clicked.

💬 Description

Changes to be made include:

• Where there are multiple child components in a code demo, a parent fragment component (<></>) is needed for React code examples
• Where a web component code demo has code in a <script> tag, these <script> tags should be moved to the bottom of the code example to ensure they work in Stackblitz
• Enable the button

Note: the list above is not exhaustive and there may be other issues that appear during the code review

💰 Use value

This will help developers who want to play around with our components.