Added webassembly support as an option to make a standalone HTML file

[Lockl00p]

Thank you for your contribution to the Fake-08 Before submitting this PR, please make sure:

• [x] This pull request is for a single Feature or BugFix
• [x] Your code builds clean without any errors on all platforms
• [x] You have added unit tests (if this is a change to the core Pico 8 emulator)