Add proc_macro attributes to attributes page

Author: Havvy

src/attributes.md

@@ -161,14 +161,20 @@ which can be used to control type layout.
 
 - `macro_reexport` on an `extern crate` — re-export the named macros.
 
-- `macro_export` - export a macro for cross-crate usage.
+- `macro_export` - export a `macro_rules` macro for cross-crate usage.
 
 - `no_link` on an `extern crate` — even if we load this crate for macros, don't
   link it into the output.
 
 See the [macros section of the first edition of the
 book](../book/first-edition/macros.html#scoping-and-macro-importexport) for more
-information on macro scope.
+information on `macro_rules` macro scope.
+
+- `proc_macro` - Defines a [bang macro].
+
+- `proc_macro_derive` - Defines a [derive macro].
+
+- `proc_macro_attribute` - Defines an [attribute macro].
 
 ## Miscellaneous attributes
 
@@ -525,9 +531,11 @@ You can implement `derive` for your own traits through [procedural macros].
 [match expressions]: expressions/match-expr.html
 [external blocks]: items/external-blocks.html
 [items]: items.html
+[attribute macro]: procedural-macros.html#attribute-macros
+[bang macro]: procedural-macros.html#bang-macros
 [conditional compilation]: conditional-compilation.html
-[trait]: items/traits.html
-[main]: crates-and-source-files.html
+[derive macro]: procedural-macros.html#derive-macros
+[trait]: items/traits.html[main]: crates-and-source-files.html
 [`Termination`]: ../std/process/trait.Termination.html
 [where clause]: items/where-clauses.html
 [trait or lifetime bounds]: trait-bounds.html