Fixed incorrect tex-code for readline

Doc/lib/libtypes.tex

@@ -676,7 +676,7 @@ Files have the following methods:
   continue reading after an \EOF{} is hit.)
 \end{funcdesc}
 
-\begin{funcdesc}{readline}optional{size}}
+\begin{funcdesc}{readline}{\optional{size}}
   Read one entire line from the file.  A trailing newline character is
   kept in the string%
 \footnote{The advantage of leaving the newline on is that an empty string 

Doc/libtypes.tex

@@ -676,7 +676,7 @@ Files have the following methods:
   continue reading after an \EOF{} is hit.)
 \end{funcdesc}
 
-\begin{funcdesc}{readline}optional{size}}
+\begin{funcdesc}{readline}{\optional{size}}
   Read one entire line from the file.  A trailing newline character is
   kept in the string%
 \footnote{The advantage of leaving the newline on is that an empty string