[dcl.enum] Avoid hanging paragraphs by moving "Enumeration declarations"

down one level to a sibling of "The using enum declaration".

[namespace.udir] Rename section to "Using namespace directive" to
further distinguish this from a using enum declaration.

Author: zygoloid

source/declarations.tex

@@ -6577,7 +6577,9 @@
 the type of the \grammarterm{id-expression} \tcode{y} is ``\tcode{const volatile double}''.
 \end{example}
 
-\rSec1[dcl.enum]{Enumeration declarations}%
+\rSec1[enum]{Enumerations}%
+
+\rSec2[dcl.enum]{Enumeration declarations}%
 \indextext{enumeration}%
 \indextext{\idxcode{\{\}}!enum declaration@\tcode{enum} declaration}%
 \indextext{\idxcode{enum}!type of}
@@ -7366,7 +7368,7 @@
 \end{codeblock}
 \end{example}
 
-\rSec2[namespace.udir]{Using directive}%
+\rSec2[namespace.udir]{Using namespace directive}%
 \indextext{using-directive|(}
 
 \begin{bnf}