Update doc/specs/stdlib_constants.md

Co-authored-by: Jeremie Vandenplas <[email protected]>

Author: MilanSkocic

doc/specs/stdlib_constants.md

@@ -30,7 +30,7 @@ The derived type [[stdlib_codata_type(module):codata_constant_type(type)]] defin
 
 * 2 type-bound procedures:
 
-    * `print` for print the values of the constant members.
+    * `print`: to print the values of the constant members;
     * `to_real` for getting the value or the uncertainty to the desired precision.
 
 A module level interface [[stdlib_codata_type(module):to_real(interface)]] is