update doc link
update doc link

SeanRBurton/regex,rust-lang/regex,rust-lang-nursery/regex,SeanRBurton/regex,rust-lang/regex,rust-lang/regex,golddranks/regex,golddranks/regex,rust-lang-nursery/regex,SeanRBurton/regex,golddranks/regex,rust-lang-nursery/regex,SeanRBurton/regex,rust-lang-nursery/regex,SeanRBurton/regex,rust-lang-nursery/regex,rust-lang/regex,rust-lang/regex