Update source/strings.tex

Co-authored-by: Johel Ernesto Guerrero Peña <[email protected]>

Author: jensmaurer

source/strings.tex

@@ -5020,7 +5020,7 @@
 \begin{itemdescr}
 \pnum
 \constraints
-\tcode{R} satisfies \tcode{ranges::contiguous_range}.
+\tcode{R} satisfies \tcode{ranges::\libconcept{contiguous_range}}.
 \end{itemdescr}
 
 \rSec2[string.view.comparison]{Non-member comparison functions}