Update docs for new command line args

[ErikGoldman]

hi friends! I noticed that osqueryi now passes the socket in the format --socket [...] instead of making it the first arg.

my quick hack was

    var socketPath string
    for index, flag := range os.Args {
        if flag == "--socket" {
            socketPath = os.Args[index+1]
        }
    }

though there should be bounds checking, etc.

just wanted to let you guys know to update the README!

[lucasmrod]

@directionless @RebeccaMahany I believe this can be closed now. The current README.md uses --socket.

[RebeccaMahany]

Agreed!