Update readme - Link to docker installation docs doesn't work.

[spothound]

Describe the bug This link doesn't work. Probably the correct one is: https://github.com/RustScan/RustScan/wiki/Installation-Guide#docker-

To Reproduce

1. Click on the link shown in the image

Expected behaviour The link should redirect to instructions on how to use the docker container as an executable, probably https://github.com/RustScan/RustScan/wiki/Installation-Guide#docker-

I will open a PR to fix this.