docs: Mintlify MDX docs + docs.json; bump Speakeasy to 1.787.0 (#382)

docs/operations/exchangeauthcodeforapikeycodechallengemethod.mdx

@@ -0,0 +1,22 @@
+---
+title: "ExchangeAuthCodeForAPIKeyCodeChallengeMethod"
+---
+
+The method used to generate the code challenge
+
+## Example Usage
+
+```python
+from openrouter.operations import ExchangeAuthCodeForAPIKeyCodeChallengeMethod
+
+# Open enum: unrecognized values are captured as UnrecognizedStr
+value: ExchangeAuthCodeForAPIKeyCodeChallengeMethod = "S256"
+```
+
+
+## Values
+
+This is an open enum. Unrecognized values will not fail type checks.
+
+- `"S256"`
+- `"plain"`