(cherry picked from commit 468264941d08b00252a4f6f081bc2dff5920bffe)

(cherry picked from commit 9f3f38acf4e1ac40e3fb2b2f86018d4cba28dd07)

(cherry picked from commit 86ff2dac05412a6ff994968c2be6122a7fcf85f9)

(cherry picked from commit d39b7b3041d1bdb9f80ab7f5878e64a3b3b79b5d)

(cherry picked from commit f25d76730b175fb680aa2770fb20a67fd858ffbb)

(cherry picked from commit db50f282bab1e98397cc7434a811b8b7da2fe6dc)

(cherry picked from commit 2b153ed074811e735aaa58d57a3fcdf7838e17f5)

Because `page.title` (and `page.url`) is already escaped and page titles served by lunrjs do not need escaping, ampersands need to be unescaped to display properly in search results.

and mention `search_exclude`