adjust tests for change to examples label typesetting

There's now a blank line between "Examples:" and the example
interaction.

scribble-test/tests/scribble/docs/eval-false.txt

@@ -1,3 +1,4 @@
 Example:
-  > #f  
+
-  #f    
+  > #f
+  #f  

scribble-test/tests/scribble/docs/print-lines.txt

@@ -1,6 +1,7 @@
 Pretty-Print-Handler Bug Example
 
-Example:                                                       
+Example:
+
   > '((x "positional 1")                                       
         (rest ("positional 2" "positional 3"))                 
         (a ())                                                 

scribble-test/tests/scribble/markdown-docs/example.md

@@ -77,8 +77,9 @@ Blah blah `(or/c string? bytes?)`.
 
 Example of Scribble `examples`:
 
+Examples:
+
 ```racket
-Examples:      
 > (define x 0) 
                
 > (displayln x)