Betaflight-Configurator 10.0.0-RC2

Alpha / test release for the post-Chrome-web-store era.

Please report issues back to https://github.com/betaflight/betaflight-configurator/issues.

Fixes:

• Fixed MacOSX build for release (#737);
• Improved build scripts (#738);
• Fixed beeper configuration (#740);
• Fixed version information when running in Chrome (#741).