Add CHANGELOG.md

Author: intjelic

CHANGELOG.md

@@ -0,0 +1,17 @@
+# Changelog
+
+This is the documentation of the
+[Term Validator](https://github.com/erlangsters/term-validator) library.
+
+## 1.0.1
+
+- Fixed tuple validator failing to validate tuples when number of elements does
+  not match the number of specified elements.
+- Fixed outdated information in `DOCUMENTATION.md` regarding options in custom
+  validators.
+- Change to Rebar3 build system (to leverage ExDoc plugin).
+- Rework in-source and out-source documentation to be nicely generated by ExDoc.
+
+## 1.0.0
+
+Initial release.