docs: change readOnlyMode on connect.md documentation (#1784)
docs: change readOnlyMode on connect.md documentation (#1784)

change the documentation by completing documentation with parameter that
didn't exist

the change is due to https://github.com/pgjdbc/pgjdbc/issues/848

Co-authored-by: Mohamed Amghari <001600bde31f87dee3f590170ae2154ac2af5882@gmail.com>
marschall/pgjdbc,pgjdbc/pgjdbc,sehrope/pgjdbc,davecramer/pgjdbc,jorsol/pgjdbc,sehrope/pgjdbc,sehrope/pgjdbc,marschall/pgjdbc,pgjdbc/pgjdbc,sehrope/pgjdbc,jorsol/pgjdbc,davecramer/pgjdbc,pgjdbc/pgjdbc,marschall/pgjdbc,jorsol/pgjdbc,jorsol/pgjdbc,davecramer/pgjdbc,pgjdbc/pgjdbc,marschall/pgjdbc,davecramer/pgjdbc