Update documentation.md
Update documentation.md

Make it clearer that 9.4 is not the current documentation
whitingjr/pgjdbc,whitingjr/pgjdbc,jorsol/pgjdbc,pgjdbc/pgjdbc,AlexElin/pgjdbc,marschall/pgjdbc,sehrope/pgjdbc,jorsol/pgjdbc,golovnin/pgjdbc,sehrope/pgjdbc,jorsol/pgjdbc,lordnelson/pgjdbc,whitingjr/pgjdbc,AlexElin/pgjdbc,pgjdbc/pgjdbc,AlexElin/pgjdbc,marschall/pgjdbc,sehrope/pgjdbc,pgjdbc/pgjdbc,davecramer/pgjdbc,lordnelson/pgjdbc,davecramer/pgjdbc,golovnin/pgjdbc,pgjdbc/pgjdbc,davecramer/pgjdbc,golovnin/pgjdbc,lordnelson/pgjdbc,marschall/pgjdbc,jorsol/pgjdbc,davecramer/pgjdbc,marschall/pgjdbc,sehrope/pgjdbc