[ios.members.static] Fix case of first letter in footnotes.

Author: zygoloid

source/iostreams.tex

@@ -1461,7 +1461,7 @@
 calling
 \tcode{iword}
 with the same index yields another reference to the same value.
-If the function fails\footnote{for example, because it cannot allocate space.}
+If the function fails\footnote{For example, because it cannot allocate space.}
 and
 \tcode{*this}
 is a base class subobject of a
@@ -1505,7 +1505,7 @@
 calling
 \tcode{pword}
 with the same index yields another reference to the same value.
-If the function fails\footnote{for example, because it cannot allocate space.}
+If the function fails\footnote{For example, because it cannot allocate space.}
 and
 \tcode{*this}
 is a base class subobject of a