Remove Chrome, Edge, Electron implementations

[4e554c4c]

These repositories are all listed as deprecated. The implementation is now internal to VSCode, and cannot be installed or used by any other editors. This means that its presence in the list is no longer useful.

[connor4312]

I don't see a need to remove them, they're still valid as implementation references.

They also can be installed in other editors, as both are traditional program-based adapters. Though there's no real reason to since the more modern js-debug exists.

[4e554c4c]

This page is not only useful for implementation references. It states

You may find these useful as reference material when writing your own debug adapter, or for use in your editor of choice.

These entries contain not only source code, but link to plugins which no longer exist.

If they are useful only to understand 'historical' implementations, perhaps they should be moved to a section that says such, and which does not contain usage instructions.

I also do not see any mention of js-debug in this list. Maybe it should be added so that those who don't use VSCode's proprietary marketplace can discover debug-adapter-protocol implementations.

[connor4312]

js-debug is the JavaScript Debugger that's linked in the table.

Maybe a * or something to indicated deprecated would be good. I think that should be applied only to repos where the owner has archived them.