readme: fix trailing whitespace
readme: fix trailing whitespace

victorenator/session,mig1098/session,wesleytodd/session,cgcardona/session,happysj/session,expressjs/session,socialrank/express-session,aboutdotme/session,coolaj86/session,tianyk/express-session-review,danielgindi/session,MadisonReed/session,tianyk/express-session-research,soulman-is-good/session,Jpunt/session,gabeio/session,sielay/session,globesherpa/session,hl198181/session,saighost/session,cnwhy/session,jasonkarns/session,fracmak/session,digitalartcrew/session