Issue

Closes #2925.

The Reference section won't need additional formatting checks because it'll be eventually generated from the well-formatted stdlib, while the Book section has way too many examples that won't pass the type checking even when wrapped in a fun example() {} body. Not to mention abundance of vertical comment alignment and eol comments that continue on the next line.

The comments part can be fixed by making them a bit more ugly, i.e., by aligning the first non-whitespace characters as opposed to // (see my comments in #2925). But the type checking bit won't be resolved that easily, since some examples simply need to show unhandled errors or invalid syntax, at the very least so that people can Google/search for their errors in the docs.