[list.erasure, list.erasure] Move long code into codeblock (#7809)

Author: hewillk

source/containers.tex

@@ -7869,7 +7869,10 @@
 \begin{itemdescr}
 \pnum
 \effects
-Equivalent to: \tcode{return erase_if(c, [\&](const auto\& elem) -> bool \{ return elem == value; \});}
+Equivalent to:
+\begin{codeblock}
+return erase_if(c, [&](const auto& elem) -> bool { return elem == value; });
+\end{codeblock}
 \end{itemdescr}
 
 \indexlibrarymember{erase_if}{forward_list}%
@@ -9761,7 +9764,10 @@
 \begin{itemdescr}
 \pnum
 \effects
-Equivalent to: \tcode{return erase_if(c, [\&](const auto\& elem) -> bool \{ return elem == value; \});}
+Equivalent to:
+\begin{codeblock}
+return erase_if(c, [&](const auto& elem) -> bool { return elem == value; });
+\end{codeblock}
 \end{itemdescr}
 
 \indexlibrarymember{erase_if}{list}%