Possible to do rollover from a solo Roth 401(k) to Roth IRA?

I’m self-employed and thinking of opening an individual Roth 401(k) account with TD Ameritrade. I would max out the employee contribution immediately and not bother with the employer match (since the employer contribution would be pre-tax and make things more complicated). I would then like to roll it over to my existing TD Ameritrade Roth IRA (because I like the characteristics of IRAs and I want to "jump start" my contributions). Is this allowed? If I worked for an employer, I believe that I’d have to wait until I left that job before I can do a rollover, right? So, under what circumstances would I be allowed to do a rollover from my individual Roth 401(k) to my Roth IRA? Would I have to stop being self-employed?