Update README.md

[mrubens]

No description provided.

[roomote-roomote]

3 issues outstanding. See task

• README.md:109-114 Render does not prompt for admin credentials or provide a setup link. The Blueprint generates SETUP_TOKEN; operators must retrieve it from the roomote-shared environment group and open /setup?token=..., so this quickstart leaves new Render deployments unable to begin onboarding.
• README.md:118-122 The installer exits for the usual non-root SSH user (deploy/install.sh requires UID 0), but this rewrite removed the root requirement and the working sudo bash invocation. Restore the non-root command or state that this command must run as root.
• README.md:128 Passing an installer option through a pipe requires bash -s -- --domain roomote.example.com; the shown command cannot accept a later flag. Production preview support also needs the app, preview, and wildcard preview DNS records documented in SELF_HOSTING.md.

_{Reviewed d5c50e3}