Distribute completion scripts along with executable

[kytrinyx]

The completion scripts currently live in the CLI website repository, which—as @QuLogic mentions here—doesn't make much sense.

We should update the bin/build-all build script to produce a directory containing:

• the executable
• the completion scripts
• a README file that explains what to do with the executable (make sure it's in your path) and the completion scripts (pick the right one, source it in your shell config)

Then tar/zip as before.