hideshow: Rework previous changes

* doc/emacs/programs.texi (Hideshow):
* etc/NEWS: Fix doc.
* lisp/progmodes/hideshow.el: Update Commentary Header.
(hs-modes-alist): Remove.
(hs--get-mode-value, hs-grok-mode-type): Rework.
* lisp/treesit.el (treesit-major-mode-setup):
* lisp/emacs-lisp/lisp-mode.el:
* lisp/nxml/nxml-mode.el:
* lisp/progmodes/cc-mode.el:
* lisp/progmodes/f90.el:
* lisp/progmodes/fortran.el:
* lisp/progmodes/hideshow.el:
* lisp/progmodes/icon.el:
* lisp/progmodes/js.el:
* lisp/progmodes/lua-mode.el:
* lisp/progmodes/python.el:
* lisp/progmodes/verilog-mode.el:
* lisp/progmodes/vhdl-mode.el:
* lisp/textmodes/bibtex.el:
* lisp/textmodes/mhtml-mode.el:
* lisp/textmodes/sgml-mode.el:
* lisp/treesit.el: Fix and rework previous changes.

doc/emacs/programs.texi

@@ -1688,8 +1688,9 @@ row).  Just what constitutes a block depends on the major mode.  In C
 mode and related modes, blocks are delimited by braces, while in Lisp
 mode they are delimited by parentheses.  Multi-line comments also
 count as blocks.
+@vindex hs-prefix-map
 
-  Hideshow mode provides the following commands:
+  Hideshow mode provides the following commands (defined in @code{hs-prefix-map}):
 
 @findex hs-hide-all
 @findex hs-hide-block
@@ -1735,7 +1736,6 @@ Hide all blocks @var{n} levels below this block
 @vindex hs-indicator-maximum-buffer-size
 @vindex hs-isearch-open
 @vindex hs-hide-block-behavior
-@vindex hs-modes-alist
   These variables can be used to customize Hideshow mode:
 
 @table @code
@@ -1782,9 +1782,6 @@ code blocks and comments), or @code{nil} (unhide neither code blocks
 nor comments).  The default value is @code{code}.
 @end table
 
-All necessary settings for each mode can be found in the variable
-@code{hs-modes-alist}.
-
 @node Symbol Completion
 @section Completion for Symbol Names
 @cindex completion (symbol names)