Added CHANGELOG, too

CHANGELOG.md

@@ -0,0 +1,17 @@
+v0.1.2.0
+=======
+
+* Added `atom` and `mkAtomParser` helper functions for new
+  user-defined atom types.
+* New parsers for various atom types:
+    * Exported parsers for individual Haskell literals, to allow
+      building new variations on the `HaskLike` atom type.
+    * Added syntaxes for arbitrary-base numeric literals in the style of
+      Common Lisp and M4
+* Added a suite of basic QuickCheck tests
+
+
+v0.1.1.0
+=======
+
+* Strongly considered but did not keep a changelog. …sorry.