bug#51532: "8.8.1 Linking Multiple Yacc Parsers" missing from "8.8 Yacc and Lex support" in HTML docs

[Zoë Sparks]

The page
https://www.gnu.org/software/automake/manual/html_node/Yacc-and-Lex.html
includes the section heading "8.8.1 Linking Multiple Yacc Parsers,"
but the section itself appears to be empty. Its (apparent) intended
contents can be reached from
https://www.gnu.org/software/automake/manual/html_node/Linking-Multiple-Yacc-Parsers.html,
and this material is also included in the PDF manual.