[lex.token] Strike useless footnote

Author: AlisdairM

source/lex.tex

@@ -874,10 +874,7 @@
 
 \pnum
 \indextext{\idxgram{token}}%
-There are five kinds of tokens: identifiers, keywords, literals,%
-\begin{footnote}
-Literals include strings and character and numeric literals.
-\end{footnote}
+There are five kinds of tokens: identifiers, keywords, literals,
 operators, and other separators.
 \indextext{whitespace}%
 Comments and the characters \unicode{0020}{space}, \unicode{0009}{character tabulation},