guide.md: add link to langpop.corger.nl

Also, fix grammar.

process/guide.md

@@ -32,9 +32,9 @@ them in rough order of importance:
 
 In addition, the following will make your task especially easy:
 
-* Dynamic typing / boxed types (specifically, you store different
-  data type in the sequential and associative structures and the
-  language keeps track of the type for you)
+* Dynamic typing / boxed types (specifically, the ability to store
+  different data types in the sequential and associative structures
+  and the language keeps track of the type for you)
 * Compound data types support arbitrary runtime "hidden" data
   (metadata, metatables, dynamic fields attributes)
 
@@ -51,6 +51,10 @@ add new implementations to mal as efficiently as possible, then you
 SHOULD find the most similar target language implementation and refer
 to it frequently.
 
+If you want a fairly long list of programming languages with an
+approximate measure of popularity, try the [Programming Language
+Popularity Chart](http://langpop.corger.nl/)
+
 
 ## Getting started
 
@@ -1119,7 +1123,6 @@ make test^quux^step8
   * `or`: "(defmacro! or (fn* (& xs) (if (empty? xs) nil (if (= 1 (count xs)) (first xs) `(let* (or_FIXME ~(first xs)) (if or_FIXME or_FIXME (or ~@(rest xs))))))))"
 
 
-
 ## TODO:
 
 * simplify: "X argument (list element Y)" -> ast[Y]