This commit adds support for [TC39 Decorator
Proposal](https://github.com/tc39/proposal-decorators).
These decorators are only available in transpiled sources - ie.
non-JavaScript files (because of lack of support in V8).
This entails that "experimental TypeScript decorators" are not available
by default
and require to be configured, with a configuration like this:
```
{
"compilerOptions": {
"experimentalDecorators": true
}
}
```
Closes https://github.com/denoland/deno/issues/19160
---------
Signed-off-by: Bartek Iwańczuk <biwanczuk@gmail.com>
Co-authored-by: crowlkats <crowlkats@toaxl.com>
Co-authored-by: Divy Srivastava <dj.srivastava23@gmail.com>
