Update usage with return values

README.md

@@ -3,12 +3,32 @@
 ## Usage
 ```ruby
 require 'dimapa'
-dmp = DiMaPa.new
+
+dmp = DiMaPa.new # or DiffMatchPatch
+
 diff = dmp.diff_main("This is a sentence.", "This is also a sentence.")
+#=> [[:equal, "This is a"], [:insert, "lso a"], [:equal, " sentence."]]
+
 dmp.diff_cleanup_semantic(diff)
+#=> nil
+
+# diff is modified in place
+diff
+#=> [[:equal, "This is "], [:insert, "also "], [:equal, "a sentence."]]
+
 patch = dmp.patch_make(diff)
+#=> [#<PatchObj:0x00005608e6ac9500 @diffs=
+#     [[:equal, "This is "], [:insert, "also "], [:equal, "a senten"]],
+#     @length1=16,
+#     @length2=21,
+#     @start1=0,
+#     @start2=0>]
+
 dmp.patch_to_text(patch)
+#=> "@@ -1,16 +1,21 @@\n This is \n+also \n a senten\n"
+
 dmp.patch_apply(patch, "This is a sentence.")
+#=> ["This is also a sentence.", [true]]
 ```
 
 A ruby implementation of the google diff-match-patch library.