Adding upstream version 0.5.1.

Signed-off-by: Daniel Baumann <daniel@debian.org>

openapi_pydantic/v3/v3_1/external_documentation.py

@@ -0,0 +1,36 @@
+from typing import Optional
+
+from pydantic import BaseModel
+
+from openapi_pydantic.compat import PYDANTIC_V2, ConfigDict, Extra
+
+_examples = [{"description": "Find more info here", "url": "https://example.com"}]
+
+
+class ExternalDocumentation(BaseModel):
+    """Allows referencing an external resource for extended documentation."""
+
+    description: Optional[str] = None
+    """
+    A short description of the target documentation.
+    [CommonMark syntax](https://spec.commonmark.org/) MAY be used for rich text 
+    representation.
+    """
+
+    url: str
+    """
+    **REQUIRED**. The URL for the target documentation.
+    Value MUST be in the form of a URL.
+    """
+
+    if PYDANTIC_V2:
+        model_config = ConfigDict(
+            extra="allow",
+            json_schema_extra={"examples": _examples},
+        )
+
+    else:
+
+        class Config:
+            extra = Extra.allow
+            schema_extra = {"examples": _examples}