fix jan comments whitespace

Author: hjwp

chapter_10_production_readiness.asciidoc

@@ -185,7 +185,9 @@ $ *docker build -t superlists . && docker run \
 ----
 
 And if you take another manual look at your site, things should look much healthier.
-Let's rerun our FTs to confirm:  // JAN: That doesn't work until you install whitenoise to venv on local machine
+Let's rerun our FTs to confirm:
+
+// JAN: That doesn't work until you install whitenoise to venv on local machine
 
 [role="small-code"]
 [subs="specialcharacters,macros"]