Guide: when introducing read_atom, don't mention complex types.

Vectors, hash-maps, and atoms wouldn't be read by read_atom anyway.
Atoms don't even have a read syntax.  While I'm there, also correct
which step keywords turn up in (step A, not step 9).

diff --git a/process/guide.md b/process/guide.md
index bdf8a76..39e9d0f 100644 (file)
--- a/process/guide.md
+++ b/process/guide.md
@@ -375,8 +375,8 @@ expression support.
   numbers (integers) and symbols. This will allow you to proceed
   through the next couple of steps before you will need to implement
   the other fundamental mal types: nil, true, false, and string. The
-  remaining mal types: keyword, vector, hash-map, and atom do not
-  need to be implemented until step 9 (but can be implemented at any
+  remaining scalar mal type, keyword does not
+  need to be implemented until step A (but can be implemented at any
   point between this step and that). BTW, symbols types are just an
   object that contains a single string name value (some languages have
   symbol types already).