chore: point to new api reference site

Signed-off-by: aramissennyeydd <aramis.sennyey@doordash.com>

docs/plugins/integrating-plugin-into-software-catalog.md

@@ -32,7 +32,7 @@ Creating the plugin...
 ### Reading entities from within your plugin
 
 You can access the currently selected entity using the backstage api
-[`useEntity`](../reference/plugin-catalog-react.useentity.md). For example,
+[`useEntity`](https://backstage.io/api/stable/functions/_backstage_plugin-catalog-react.index.useEntity.html). For example,
 
 ```tsx
 import { useEntity } from '@backstage/plugin-catalog-react';

docs/plugins/structure-of-a-plugin.md

@@ -82,7 +82,7 @@ export const ExamplePage = examplePlugin.provide(
 
 This is where the plugin is created and where it creates and exports extensions
 that can be imported and used in the app. See reference docs for
-[`createPlugin`](../reference/core-plugin-api.createplugin.md) or introduction to
+[`createPlugin`](https://backstage.io/api/stable/functions/_backstage_core-plugin-api.index.createPlugin.html) or introduction to
 the new [Composability System](./composability.md).
 
 ## Components