pw_async: Add module metadata

Bug: 339741960
Change-Id: I908fa2b645442b01f904c1d444a20f2d8e1152e5
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/214499
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>
Reviewed-by: Taylor Cramer <cramertj@google.com>
Commit-Queue: Auto-Submit <auto-submit@pigweed-service-accounts.iam.gserviceaccount.com>
Presubmit-Verified: CQ Bot Account <pigweed-scoped@luci-project-accounts.iam.gserviceaccount.com>
Pigweed-Auto-Submit: Kayce Basques <kayce@google.com>

docs/module_metadata.json

@@ -22,6 +22,13 @@
       "GN"
     ]
   },
+  "pw_async": {
+    "tagline": "Portable APIs for asynchronous code",
+    "status": "deprecated",
+    "languages": [
+      "C++"
+    ]
+  },
   "pw_async2": {
     "tagline": "Cooperative async tasks for embedded",
     "status": "experimental",

docs/module_metadata_schema.json

@@ -38,7 +38,8 @@
           "enum": [
             "stable",
             "unstable",
-            "experimental"
+            "experimental",
+            "deprecated"
           ]
         },
         "tagline": {

pw_async/backends.rst

@@ -1,8 +1,11 @@
 .. _module-pw_async-backends:
 
-==================
+=================
 pw_async backends
-==================
+=================
+.. pigweed-module-subpage::
+   :name: pw_async
+
 .. TODO: b/323607687 - Add backend guidance here
 
 .. toctree::

pw_async/docs.rst

@@ -1,8 +1,10 @@
 .. _module-pw_async:
 
-================
+========
 pw_async
-================
+========
+.. pigweed-module::
+   :name: pw_async
 
 --------
 Overview