If you want to have the identifiers from your source code automatically hyper-linked, you likely need to do two things.
One is that you need to add for-label
requires for any libraries that you want Scribble to recognize. For example, you probably want (require (for-label 2htdp/image))
. See this subsection of the docs for more on that.
The other is that if you're hosting the Scribble documents online the documentation links need to point somewhere, and you need to specify where. You can do that with a command-line flag. Something like this:
scribble --html +m --redirect-main http://docs.racket-lang.org/ document.scrbl
You can use different documentation URLs. For example, you might instead link to the pre-release snapshot documentation at http://www.cs.utah.edu/plt/snapshots/current/doc/.
For more details, there is a subsection of the Scribble documentation about handling cross-references: http://www.cs.utah.edu/plt/snapshots/current/doc/scribble/running.html#%28part._xref-flags%29