Add ability to see Beta release notes

Description of the issue:
When I update the browser and click on the Version string, I’d like to see the beta release notes.

Steps to Reproduce (add as many as necessary): 1. 2. 3.

  1. Open the browser and click About Brave
  2. Click on the Version string to open the release notes.

Reproduces how often:
All the time.

Brave Build and Version(ex., "Brave Beta, v1.14.73):
Version 1.19.77 Chromium: 87.0.4280.101 (Official Build) beta (64-bit)

Reproducible on current live release (yes/no):

Additional Information: