Document maintenance_intent

Signed-off-by: ArthurW <arthur@tarides.com>
Signed-off-by: Marek Kubica <marek@tarides.com>

Author: art-w

doc/changes/11274.md

@@ -0,0 +1 @@
+- Support for opam `(maintenance_intent ...)` in dune-project (#11274, @art-w)

doc/howto/opam-file-generation.rst

@@ -81,13 +81,15 @@ For example, if your opam file looks like:
      "conduit-async" { >= "1.0.3" }
      "async" { >= "v0.10.0" }
    ]
+   x-maintenance-intent: [ "(latest)" ]
 
 You can express this as::
 
    (source (github mirage/ocaml-cohttp))
    (license ISC)
    (authors "Anil Madhavapeddy" "Rudi Grinberg")
    (maintainers "team@mirage.org")
+   (maintenance_intent "(latest)")
 
    (package
     (name cohttp-async)

doc/reference/dune-project/generate_opam_files.rst

@@ -63,6 +63,19 @@ defined in the project:
        "Jane Doe <jane.doe@example.com>"
        "John Doe <john.doe@example.com>")
 
+.. _maintenance_intent:
+.. describe:: (maintenance_intent <strings>)
+
+   .. versionadded:: 3.18
+
+   Specify the `opam maintenance intent <https://github.com/ocaml/opam-repository/blob/master/governance/policies/archiving.md#specification-of-the-x--fields-used-in-the-archiving-process>`__.
+
+   Example:
+
+   .. code:: dune
+
+      (maintenance_intent "(latest)")
+
 .. describe:: (source ...)
 
    .. versionadded:: 1.7

doc/reference/dune-project/package.rst

@@ -60,6 +60,13 @@ package
 
       The same as (and takes precedences over) the corresponding global field.
 
+   .. describe:: (maintenance_intent ...)
+
+      .. versionadded:: 3.18
+
+      The same as (and takes precedences over) the corresponding global field.
+      See :doc:`the global field for details </reference/dune-project/generate_opam_files>`.
+
    .. describe:: (source ...)
 
       .. versionadded:: 2.0