improvements to markdown doc

README.md

@@ -53,11 +53,11 @@ Given a list of points, constructs and returns a K-D tree object.
 
 <procedure>kd-tree? :: KD-TREE -> BOOL </procedure>
 
-Returns {{#t}} if the given object is a K-D tree, {{#f}} otherwise.
+Returns `#t` if the given object is a K-D tree, `#f` otherwise.
 
 <procedure>kd-tree-empty? :: KD-TREE -> BOOL  </procedure>
 
-Returns {{#t}} if the given K-D tree object is empty, {{#f}} otherwise.
+Returns `#t` if the given K-D tree object is empty, `#f` otherwise.
 
 <procedure>kd-tree-is-valid? :: KD-TREE -> BOOL  </procedure>
 
@@ -79,8 +79,8 @@ Returns a list with the points contained in the tree.
 
 <procedure>kd-tree->list* :: KD-TREE -> (INT . POINT3D) LIST </procedure>
 
-Returns a list where every element has the form {{(i . p)}}, where i
-is the relative index of this point, and {{p}} is the point.
+Returns a list where every element has the form `(i . p)`, where `i`
+is the relative index of this point, and `p` is the point.
 
 <procedure>kd-tree-subtrees :: KD-TREE -> KD-TREE LIST</procedure>