readme: add note

README.md

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 The whole thing was vibe coded using Shelley, the built-in AI chatbot in an exe.dev VM. I plan to use this to understand Go project structure. I haven't audited shit -- not even the build and run instructions below this section -- so just be aware of that. Afaik Shelly did pretty good though and it both amazes and scares the shit out of me that AI agents are capable of this.
 
-You can try it out on: https://cooki.exe.xyz
+You can try it out on: https://cooki.exe.xyz (due to some quirks of exe.dev VMs, it only works if you use `https` and not `http` in the url)
 
 If you see "Service unavailable" that means I -- intentionally or unintentionally -- shut down the process. Feel free to dm me on bluesky to request to turn it back on. Response not guaranteed (but most of the time i will, unless im rly busy or taking a break from the internet,  just thought it'd be safer to say that)