[range.view] Move description above the definitions

Author: JohelEGP

source/ranges.tex

@@ -850,6 +850,10 @@
 which cannot be done in constant time.
 \end{example}
 
+\pnum
+Since the difference between \libconcept{Range} and \libconcept{View} is largely
+semantic, the two are differentiated with the help of \tcode{enable_view}.
+
 \indexlibrary{\idxcode{enable_view}}%
 \indexlibrary{\idxcode{View}}%
 \begin{itemdecl}
@@ -862,10 +866,6 @@
 \end{itemdecl}
 
 \begin{itemdescr}
-\pnum
-Since the difference between \libconcept{Range} and \libconcept{View} is largely
-semantic, the two are differentiated with the help of \tcode{enable_view}.
-
 \pnum
 For a type \tcode{T}, the default value of \tcode{enable_view<T>} is:
 \begin{itemize}