chore: add a notice about the repository archival

[brooksmtownsend]

New wasmCloud users and community members who visit https://github.com/wasmCloud/wash might be surprised to learn that the repository has been archived, and not know where to go to contribute code.

This commit adds a Github-native warning to the top of the repository noting the move that's happened and where people can find the new code.

Feature or Problem

Related Issues

Release Information

Consumer Impact

Testing

Built on platform(s)

• [ ] x86_64-linux
• [ ] aarch64-linux
• [ ] x86_64-darwin
• [ ] aarch64-darwin
• [ ] x86_64-windows

Tested on platform(s)

• [ ] x86_64-linux
• [ ] aarch64-linux
• [ ] x86_64-darwin
• [ ] aarch64-darwin
• [ ] x86_64-windows

Unit Test(s)

Acceptance or Integration

Manual Verification

[vados-cosmonic]

:+1: approved

[brooksmtownsend]

Couldn't push to your fork @vados-cosmonic so I just opened #960