add spec with default parameter

.gitignore

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+.idea

openapi.yaml

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+---
+openapi: 3.0.0
+info:
+  title: Example
+  version: '1'
+  description: ''
+servers:
+- url: https://example.com
+paths:
+  "/example":
+    get:
+      operationId: Example
+      parameters:
+        - $ref: "#/components/parameters/ResultsPerPageQueryParam"
+      responses:
+        '200':
+          description: example
+components:
+  parameters:
+    ResultsPerPageQueryParam:
+      description: The number of results to return per page (max 100)
+      in: query
+      name: results_per_page
+      schema:
+        type: integer
+        format: int64
+        maximum: 100
+        default: 25
+  responses: {}