Revert "correct name of the server package (wiki-node-server)"

This reverts commit 46a7381c30e5cd7e1aeb02b71cbe3642ca111f52.
ReadMe example config.json copied over from fedwiki/wiki-node-server@5e0968f (thanks Jonan Scheffler)
package.json - description updated
Developer notes in contributing.md, rather than ReadMe.md