Added two new background videos

[rivenintech]

Description

While browsing YouTube I found two cool copyright-free background videos that I saw being used in other shorts. I decided that adding them might be a good idea to give users more background videos to choose from.

Issue Fixes

None

Checklist:

• I am pushing changes to the develop branch
• I am using the recommended development environment
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have formatted and linted my code using python-black and pylint
• I have cleaned up unnecessary files
• My changes generate no new warnings
• My changes follow the existing code-style
• My changes are relevant to the project

Any other information (e.g how to test the changes)

None