partial functions added

src/koans/about_partial_functions.clj

@@ -0,0 +1,9 @@
+(meditations
+  "Partial functions allow procrastination"
+  (= 20 (let [multiply-by-5 (partial * 5)]
+          (___ __)))
+
+  "Don't forget: first things first"
+  (= [__ __ __ __]
+     (let [ab-adder (partial concat [:a :b])]
+       (ab-adder [__ __]))))