[vector.bool.pscp] say "vector primary template" (#8351)

Not primary vector template.

Author: jwakely

source/containers.tex

@@ -10575,7 +10575,7 @@
 
 \pnum
 Unless described below, all operations have the same requirements and
-semantics as the primary \tcode{vector} template, except that operations
+semantics as the \tcode{vector} primary template, except that operations
 dealing with the \tcode{bool} value type map to bit values in the
 container storage and
 \tcode{allocator_traits::construct}\iref{allocator.traits.members}