.buffer spec formatting is broken

[domenic]

https://github.com/WebAssembly/threads/blob/d8b13eb4efb4e88ab7c21d01385de1367f273ef4/proposals/threads/Overview.md#webassemblymemoryprototypebuffer

Step 4 appears to be lots of steps squished together. I'm surprised people were able to implement this :)

[binji]

Thanks, fixed in #100.