14.3 - helpfully implied code sample is broken

As a new user, I spent a while confused when flycheck told me the code sample I'd typed in was invalid. I ended up figuring out some of what comes after the code sample more painfully by myself because there was no indication that it was broken in the text beforehand. This one line change makes it clear that the code following it is an experiment that may not work rather than something to assume just works.

src/doc/guide.md

@@ -1901,8 +1901,8 @@ result is a link to
 click on that result, we'll be taken to its documentation page.
 
 This page shows us a few things: the type signature of the function, some
-explanatory text, and then an example. Let's modify our code to add in the
-`random` function:
+explanatory text, and then an example. Let's try to modify our code to add in the
+`random` function and see what happens:
 
 ```{rust,ignore}
 use std::io;