Links in references of state-of-grpc-web post are not hyperlinks

[Johan Brandhorst-Satzkorn]

See https://grpc.io/blog/state-of-grpc-web#references

This seems to have something to do with your markdown renderer as it is working as expected in my own blog: https://jbrandhorst.com/post/state-of-grpcweb/#references.

I'm gonna try to fix this with explicit <a> tags.