(TK-343) Add `:normalize-request-uri` docs to the README.md
(TK-343) Add `:normalize-request-uri` docs to the README.md

This commit adds some documentation about the `:normalize-request-uri`
option to the `add-*-handler` documentation in the README.md file.

camlow325/trapperkeeper-webserver-jetty9,puppetlabs/trapperkeeper-webserver-jetty9,camlow325/trapperkeeper-webserver-jetty9,rlinehan/trapperkeeper-webserver-jetty9,puppetlabs/trapperkeeper-webserver-jetty9,rlinehan/trapperkeeper-webserver-jetty9