OCaml: Add information in the manual language docs for OCaml

CHANGELOG updated

Author: mattiasdrp

Diff for: CHANGELOG.org

@@ -35,6 +35,7 @@
   * Add support for [[https://github.com/c3lang/c3c][c3 language]] (requires [[https://github.com/c3lang/c3-ts-mode][c3-ts-mode]] and [[https://github.com/pherrymason/c3-lsp][c3lsp]]).    
   * Drop support for emacs 27.1 and 27.2
   * Add ~lsp-nix-nixd-server-arguments~ to allow passing arguments to the ~nixd~ LSP.
+  * Improve the lsp-ocaml client (see [[https://github.com/emacs-lsp/lsp-mode/issues/4731][#4731]] for the follow-up issue. MRs: [[https://github.com/emacs-lsp/lsp-mode/pull/4741][#4741]], [[https://github.com/emacs-lsp/lsp-mode/pull/4732][#4732]])
 
 ** 9.0.0
   * Add language server config for QML (Qt Modeling Language) using qmlls.

Diff for: docs/manual-language-docs/lsp-ocaml.md

@@ -8,6 +8,34 @@ root_file: docs/manual-language-docs/lsp-ocaml.md
 
 ### Commands
 
+#### `lsp-ocaml-type-enclosing`
+
+Gets the type of ident under the cursor. It will highlight the ident and display its type.
+
+When this function is called it will create a transient keymap `lsp-ocaml-type-enclosing-map` that allows to do the following things:
+- Increase/decrease the number of aliases expansions. As an example, suppose we want to type `h` in the following expression:
+  ```ocaml
+  type t = A | B
+  let h : t = A
+  ```
+  - The lowest verbosity will give `type t`
+  - The next verbosity will give `type t = A | B`
+- Go up/down the enclosing type (bound to `C-<up>/<down>` by default). As an example:
+  ```ocaml
+  module A = struct
+    let h : t = A
+    let f () = ()
+
+    (** Test doc *)
+    let g (f: 'a -> 'b) a = f a
+  end
+  ```
+  - Typing on the last `a` will show `'a`
+  - Going up will highlight `f a` of type `'b`
+  - Going up will highlight `(f: 'a -> 'b) a = f a` of type `('a -> 'b) -> 'a -> 'b`
+  - Going up will highlight the whole module and display its entire type
+- Copy the current type (bound to `C-w` by default)
+
 #### `lsp-ocaml-find-alternate-file`
 
 Find the interface corresponding to an implementation or the implementation corresponding to an interface.