Build instructions should read "# or"

[alandefreitas]

@alandefreitas , your reply was detailed, and at the moment I am not following the thread. Which leads through mrdocs, antora, command-line options, and so on. That's ok. How about this:

Pull request 283 only fixes the macOS issue (which I believe it does.) Done.
In another PR, when you have a chance, you could update the README. Considering these points:

• "We need your # or comment."
• The README mentions multiple output dirs. Open file:///home/user/path/to/antora/build/develop/doc and Open file:///home/user/path/to/antora/build/doc. If switching to or it would only be one directory?
• A suggestion that the output location is described this way. (not required).

/home/user/website-v2-docs/build

or

/home/user/website-v2-docs/build (or wherever you have checked out the repository) 

• anything else

Originally posted by @sdarwin in https://github.com/boostorg/website-v2-docs/issues/283#issuecomment-2284357049

[sdarwin]

or,

the current README might be showing actual script output:

Site generation complete!
Open file:///home/user/path

However, if that is 'computed', the README is not able to 'compute' so it could explain the results in a different way, with this sort of text.

After running sitedoc.sh, the generated files will be found in the build/ directory. Open build/index.html in a browser.