simplifies playground motivation

basics.html

@@ -182,8 +182,7 @@
             - test stuff without interfering
               - throw away if garbage
               - integrate if good
-            - switch back and forth
-            - (done right) decision based on regression testing
+            - switch back and forth without pain
           </section>
 
           <section id="motivation-collaboration-1" data-markdown>

img/motivation-throwaway-playground.dot

@@ -6,9 +6,9 @@ digraph {
 
         node [color = limegreen]
 
-        master3[label = "ebe0262"]
-        master2[label = "03f4f8d"]
-        master1[label = "62a0ee9"]
+        master3[label = "..."]
+        master2[label = "..."]
+        master1[label = "..."]
 
         master3 -> master2 -> master1
     }
@@ -18,8 +18,8 @@ digraph {
 
         node [color = orchid]
 
-        playground2[label = "8b29f74"]
-        playground1[label = "7f295dd"]
+        playground2[label = "visualization"]
+        playground1[label = "methods"]
 
         playground2 -> playground1
     }