New example site, popup positioning

[dylandbl]

Summary

1. Created a new example site.
2. Added a new feature to the popup for easy, relative positioning.
3. Fixed but where "X" close button might be covered by the header.
4. Added border to popup.

Why this change is needed

1. If a picture is worth a thousand, an interactive picture must be worth a million.
2. It was a planned feature, but it ended up becoming core to the layout of the example site and was developed in tandem.
3. Users would not be able to click the close button.
4. Creates clear division between the popup and the background.

What was done

1. Created a lot of new files, reorganised example's App.tsx.
2. i. Added new prop, placement for positioning of the popup relative to its trigger.
   ii. Moved height and width calculation functions into new file, which also contains placement calculation.
3. Moved the close button below the header in the DOM.

[dylandbl]

Need to update package.json version for both RQR and example.

Need to update README with new prop info.