Update and organize the Keywords table

* Add two missing keywords, `Self` and `proc`
* Fix some mis-alphabetized keywords

Author: mbrubeck

src/doc/reference.md

@@ -196,10 +196,11 @@ grammar as double-quoted strings. Other tokens have exact rules given.
 | fn       | for      | if       | impl     | in      |
 | let      | loop     | macro    | match    | mod     |
 | move     | mut      | offsetof | override | priv    |
-| pub      | pure     | ref      | return   | sizeof  |
-| static   | self     | struct   | super    | true    |
-| trait    | type     | typeof   | unsafe   | unsized |
-| use      | virtual  | where    | while    | yield   |
+| proc     | pub      | pure     | ref      | return  |
+| Self     | self     | sizeof   | static   | struct  |
+| super    | trait    | true     | type     | typeof  |
+| unsafe   | unsized  | use      | virtual  | where   |
+| while    | yield    |          |          |         |
 
 
 Each of these keywords has special meaning in its grammar, and all of them are