feat: automatically generate postman collection from the openapi spec

* feat: add speccy and openapi2postmanv2 as deps

* feat: organize postman folders like our docs

* chore: generate postman on gh-pages action

* chore: change link to download Postman collection from local file

Author: rafaelcr

.github/workflows/gh-pages.yml

@@ -31,7 +31,7 @@ jobs:
         working-directory: docs
 
       - name: Generate and deploy gh-pages
-        run: npm run generate:types && npm run generate:docs
+        run: npm run generate:types && npm run generate:docs && npm run generate:postman
         working-directory: docs
 
       - name: Publish test coverage report

docs/openapi.yaml

@@ -16,7 +16,7 @@ info:
 
     It is comprised of two parts; the Stacks Blockchain API and the Stacks Core API.
 
-    [![Run in Postman](https://run.pstmn.io/button.svg)](https://app.getpostman.com/run-collection/614feab5c108d292bffa#?env%5BStacks%20Blockchain%20API%5D=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)
+    <a href="collection.json" download="collection.json">Download Postman collection</a>
 
 paths:
   /extended/v1/faucets/stx: