added a bunch of missing descriptions for grammar rules in grammar.pegjs. make sure that a description is not repeated in smart error message. comment rules should not use sym_x rules since you should not be able to put a space between the two symbols at the start and/or end of a comment. refs #2

Author: nwronski

CHANGELOG.md

@@ -2,6 +2,16 @@
 All notable changes to this project will be documented in this file.
 
 ## [Unreleased][unreleased]
+### Changed
+- added a bunch of missing descriptions for grammar rules in `grammar.pegjs`
+- make sure that a `description` is not repeated in smart error message
+
+### Notes
+- `comment` rules should not use `sym_*` rules since you should not be able to put a space between the two symbols at the start and/or end of a comment.
+
+  ```
+  SELECT * - - not valid but is being accepted
+  ```
 
 ## [v0.9.1] - 2015-07-05
 ### Changed