[basic.def] Fix typo "braced-enclosed".

Author: zygoloid

source/basic.tex

@@ -113,7 +113,7 @@
 the
 \indextext{declaration!\idxcode{extern}}%
 \tcode{extern} specifier\iref{dcl.stc} or a
-\grammarterm{linkage-specification}\footnote{Appearing inside the braced-enclosed
+\grammarterm{linkage-specification}\footnote{Appearing inside the brace-enclosed
 \grammarterm{declaration-seq} in a \grammarterm{linkage-specification} does
 not affect whether a declaration is a definition.}\iref{dcl.link}
 and neither an \grammarterm{initializer} nor a