Update README with a new echo package with bug fixes

[canidam]

The existing package has a critical bug, which I spent an hour to figure out it was in the package: https://github.com/spazzymoto/echo-scs-session/issues/1

Since the repo isn't maintained anymore, I decided to fix it on a fork. The fork contains similar logic to how the scs package handles session cookies. This solves the expiry problem and actually allow permanent session cookies.

I updated the README to point to the fork, so people won't encounter this annoying bug.