Add PWA support

[gabrielclaudino]

Hello. I add the PWA support, and I believe it closes #15 issue.

Description

In order to created the manifest.json file I had to make some decisions:

• Logo creation: I didn't find any logo in the project, so I created a very simple one just with the name of the app using a font based on the film (Ringbearer);
• The theme color is the one used in the app header;
• The description was based on what was written on the website;

These were just decisions I made to build the file and it can be changed as you wish.

Other than that, the changes were simple, I added the icons to the public folder, created some tags in the HTML header, registered the service worker, and took the opportunity to correct an internal hyperlink problem that I found on Documentation.jsx;

[gitfrosh]

Hi @gabrielclaudino, thanks for this contribution! 👍🏻 It's so cool you took the time to create and add the icons!
I'll merge your pull request and the changes will go to production with the next release.
Cheers 🚀