docs: add openapi-code-generator.

adds https://github.com/mnahkies/openapi-code-generator/ / https://openapi-code-generator.nahkies.co.nz/ to the list.

it currently supports generating typescript client sdks based on fetch / axios, and server routing / request+response validation based on koa (choice of zod / joi for runtime validation).

an experimental nextjs server implementation is in the works (mnahkies/openapi-code-generator#152), and my longer term plan is to add other languages such as kotlin to the set of templates.

_data/tools.yml

@@ -2804,6 +2804,19 @@
   v3: true
   v3_1: true
 
+- name: openapi-code-generator
+  category:
+    - sdk
+    - server
+  language: TypesScript
+  link: https://openapi-code-generator.nahkies.co.nz
+  description: >
+    A code generation tool for openapi 3 / 3.1, and typespec specifications, 
+    primarily aimed at generating typescript client SDKs, and server stubs, 
+    with an emphasis on compile & runtime safety.
+  v3: true
+  v3_1: true
+
 - name: openapi-merge
   category: converters
   language: TypeScript