[OIDC] User docs

docs/user/main.py

@@ -1,3 +1,20 @@
+from pathlib import Path
+
+
+OIDC_PUBLISHING = """
+!!! info
+
+    OpenID Connect publishing functionality is currently in closed beta.
+
+    You can register for the closed beta using
+    [this form](https://forms.gle/XUsRT8KTKy66TuUp7).
+
+    **NOTE**: Access to the OIDC beta is provided on a *per-user* basis: users
+    can register OIDC publishers against projects once added to the beta, but
+    other maintainers/owners of the project can't modify OIDC settings unless
+    they're *also* in the beta.
+"""
+
 ORG_ACCOUNTS = """
 !!! info
 
@@ -8,9 +25,9 @@
     to be one of the first to know how you can begin using them.
 """
 
-PREVIEW_FEATURES = {
-    'org-accounts': ORG_ACCOUNTS
-}
+PREVIEW_FEATURES = {"oidc-publishing": OIDC_PUBLISHING, "org-accounts": ORG_ACCOUNTS}
+
+_HERE = Path(__file__).parent.resolve()
 
 
 def define_env(env):
@@ -19,3 +36,8 @@ def define_env(env):
     @env.macro
     def preview(preview_feature):
         return PREVIEW_FEATURES.get(preview_feature, "")
+
+    @env.macro
+    def image(name):
+        path = _HERE / "assets" / name
+        return f"![]({path})"