Cosmetic improvements in the manual

doc/crossrefenum.md

@@ -147,7 +147,7 @@ you can do:
 
 The macro `\crossrefenum` has the following syntax:
 
-  > \\crossrefenum\[_type_\]\[_print prefix?_\]{_enumeration_}
+  > \\crossrefenum[\<type\>][\<print prefix?\>]{\<enumeration\>}
 
   * _type_ is the type of the references. Built-in possible values are:
     * For LaTeX and ConTeXt: `page`, `note`, `pagenote`;
@@ -204,7 +204,7 @@ In this respect, “default” settings may be set be the user.
 
 The key-value interface has the following syntax:
 
-  > \\crfnmsetup\[_“default” or type_\]{ _key1_ = _value1_, _key2_ = _value2_, … }
+  > \\crfnmsetup[<“default” or type>]{ \<key1\> = \<value1\>, <…> }
 
 _type_ is a single or a double type (e.g. `page` or `pagenote`).
 The spaces around the equal signs and the commas are optional and ignored;