Add a "Back to Top" button to the site

[Smokyish]

We have pages that currently run long as well as a menu on the sidebar that is static and stays at the top of the page. A "Back to Top" button would improve the user experience removing the need to scroll the pages to the top to find the menu.

This button should be positioned on the bottom right corner of the pages where we have space. It should also follow similar styling that is used for button on the Forum as well as the Blog. The color scheme should follow the coloring used in the theme.

Example button style from the Forum

Example button from the Blog

[LalitNM]

@Smokyish! Assign this to me. I can do this.

[Smokyish]

@LalitNM Done! :)