Hub 3.0 support

What's Changed

• base: add argument for changing the ubuntu image by @shr-project in #127
• Structure for multi-base-os-support by @webbertakken in #131
• Fix description update workflow by @webbertakken in #133
• Bump actions/cache from 2.1.6 to 2.1.7 by @dependabot in #130
• Initial Support for Windows Based Docker Images by @AndrewKahr in #134
• Install Unity Hub from Unity Hub Debian repository by @bkslasher in #138
• Bump ruairidhwm/action-cats from 1.0.1 to 1.0.2 by @dependabot in #136

New Contributors

• @AndrewKahr made their first contribution in #134

Full Changelog: v0.15...v0.16.0