updated README with links

Author: jon-batscha

README.md

@@ -1,7 +1,7 @@
 # Klaviyo's OpenAPI Specification
 
-This repo is to store versioned copies of our OpenAPI spec.
+This repo contains versioned copies of our [OpenAPI spec](https://www.openapis.org/).
 
-This is the same spec we use to generate our API Docs, as well as our latest SDKs.
+This is the same spec we use to generate our [API Docs](https://developers.klaviyo.com/en), as well as our latest [SDKs](https://developers.klaviyo.com/en/docs/sdk_overview).
 
 You can find the general spec (and soon, SDK/language-specific specs) in the `openapi` folder