fix(tuareg.el): Fix and improve Emacs bindings

(following the discussion in #273)

CHANGES.md

@@ -1,7 +1,8 @@
 unreleased
 ----------
 
-* Add support for [opam-switch-mode](https://github.com/ProofGeneral/opam-switch-mode): enable the mode with <kbd>M-x opam-switch-mode</kbd> or add an automatic hook `(add-hook 'tuareg-mode-hook #'opam-switch-mode)`.
+* Add support for [opam-switch-mode](https://github.com/ProofGeneral/opam-switch-mode): you can enable the mode with <kbd>M-x opam-switch-mode</kbd> or add an automatic hook `(add-hook 'tuareg-mode-hook #'opam-switch-mode)`.
+* Fix keybindings to comply with [GNU Emacs' Key Binding Conventions](https://www.gnu.org/software/emacs/manual/html_node/elisp/Key-Binding-Conventions.html) (unbind <kbd>C-c ?</kbd> as <kbd>C-c `</kbd> is already set; unbind <kbd>C-c C-h</kbd> and bind <kbd>C-h .</kbd> instead). See also [this issue](https://github.com/ocaml/merlin/issues/1386#issuecomment-1701567716).
 
 3.0.1 2022-09-29
 ----------------

tuareg.el

@@ -1506,7 +1506,6 @@ Run only once."
     (define-key map "\C-c\C-i" #'tuareg-interrupt-ocaml)
     (define-key map "\C-c\C-k" #'tuareg-kill-ocaml)
     (define-key map "\C-c`" #'tuareg-interactive-next-error-source)
-    (define-key map "\C-c?" #'tuareg-interactive-next-error-source)
     (define-key map "\C-c.c" #'tuareg-insert-class-form)
     (define-key map "\C-c.b" #'tuareg-insert-begin-form)
     (define-key map "\C-c.f" #'tuareg-insert-for-form)
@@ -1527,7 +1526,7 @@ Run only once."
       (define-key map [?\C-c ?\C-i] #'ocaml-add-path)
       (define-key map [?\C-c ?\[] #'ocaml-open-module)
       (define-key map [?\C-c ?\]] #'ocaml-close-module)
-      (define-key map [?\C-c ?\C-h] #'caml-help)
+      (define-key map [?\C-h ?.] #'caml-help)
       (define-key map [?\C-c ?\t] #'tuareg-complete))
     map)
   "Keymap used in Tuareg mode.")
@@ -3528,7 +3527,6 @@ OCaml uses exclusive end-columns but Emacs wants them to be inclusive."
     (define-key map "\C-c\C-k" #'tuareg-kill-ocaml)
     (define-key map "\C-c\C-z" #'tuareg-switch-to-recent-buffer)
     (define-key map "\C-c`" #'tuareg-interactive-next-error-repl)
-    (define-key map "\C-c?" #'tuareg-interactive-next-error-repl)
     (define-key map "\C-m" #'tuareg-interactive-send-input)
     (define-key map [(shift return)]
       #'tuareg-interactive-send-input-end-of-phrase)