make readme more informative, add help text

README.md

@@ -1,3 +1,9 @@
-# pizzacalc
+# Pizza Calculator
+Makes a two (15m) rise pan pizza, baked at 550f. Limited to circular cast iron pans.
 
-Pizza Calculator, makes a two (15m) rise pan pizza.
+```
+Usage: ./pizza.sh [-h] [-f <N>] [<flour weight>g|<pan diameter>(in|inch|")]
+Options:
+	-h	Print this help
+	-f <N>	Set flour per square inch
+```

pizza.sh

@@ -4,7 +4,7 @@ FSI=2.12206590789 # grams of Flour per Square Inch of pan
 function pizzahelp {
 	echo "Pizza Calculator: The pizza script you never asked for"
 	echo
-	echo "Usage: ./pizza.sh [-h] [-f] [<flour weight>g|<pan diameter>(in|inch|\")]"
+	echo "Usage: ./pizza.sh [-h] [-f <N>] [<flour weight>g|<pan diameter>(in|inch|\")]"
 	echo "Options:"
 	echo "	-h	Print this help"
 	echo "	-f <N>	Set flour per square inch"