The text is somewhat scattered by the compilation process, but you can extract it easily enough from the source text. For instance, here's a Perl script:
Save it, enter
perl -f "/path/to/script.perl" < "/path/to/project.inform/Source/story.ni" > "/path/to/file/where/strings/should/be/saved.text"
on the command line, and you should get a list of texts. You might have to repeat the process for any extensions you're including. (I am assuming, of course, that you have Perl installed.)