[meta.reflection.queries] Add period to end of sentence

Author: Andreas-Krug

source/meta.tex

@@ -3753,7 +3753,7 @@
 \begin{itemdescr}
 \pnum
 \returns
-\tcode{true} if \tcode{r} represents a type alias or namespace alias, respectively
+\tcode{true} if \tcode{r} represents a type alias or namespace alias, respectively.
 Otherwise, \tcode{false}.
 \begin{note}
 A specialization of an alias template is a type alias.