Update wheat-sourdough.tex (#387)

Corrects relative scales of dough to starter when considering refreshing.

book/wheat-sourdough/wheat-sourdough.tex

@@ -135,7 +135,7 @@ \section{Readying your starter}%
 Some people use a 1:1:1 ratio to refresh the starter. This would
 be one part of the old starter (\qty{10}{\gram} for instance), 1 part of flour,
 and one part of water. I~think this is utter rubbish. As mentioned
-your starter is a gigantic dough. You would never opt for a 1:1:1 ratio to
+your starter is a miniature dough. You would never opt for a 1:1:1 ratio to
 make dough. You might use a maximum of \qty{20}{\percent} starter to
 make dough. That's why I~advocate using a 1:5:5 ratio or a
 1:10:10 ratio depending on how ripe your starter is. As I~almost