Adds SwiftUI Beta Video to README

[brianlombardo]

Linked Issue:

Checklist:

• Did you sign the Contributor License Agreement?
• Is the linter reporting 0 errors?
• Did you comply with our styleguide?
• Is there adequate test coverage for your new code?
• Does the CI pipeline pass?
• Did you update the documentation?
• Did you update the sample app?
• Do we need to increment the minor/major version?
• Did you change the public API?
• Have you done everything you can to make sure that errors that can occur are compile-time errors, and if they have to be runtime do you have adequate tests and documentation around those runtime errors? For more details.

[codecov-commenter]

Codecov Report

Merging #115 (d1dfa4e) into main (5c2e4a1) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main     #115   +/-   ##
=======================================
  Coverage   93.98%   93.98%           
=======================================
  Files          75       75           
  Lines        1813     1813           
=======================================
  Hits         1704     1704           
  Misses        109      109           

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