[simd.expos.defn] Fix missing paragraph break (#8028)

Author: mattkretz

source/numerics.tex

@@ -16321,6 +16321,7 @@
 \begin{itemdescr}
 \pnum
 Let \tcode{x} denote an lvalue of type \tcode{const T}.
+
 \pnum
 \tcode{\exposid{make-compatible-simd-t}<V, T>} is an alias for
 \begin{itemize}