doc(v7): Add package discontinuity notes to remaining discontinued packages (#12347)

Author: Lms24

packages/hub/README.md

@@ -10,6 +10,12 @@
 [![npm dm](https://img.shields.io/npm/dm/@sentry/hub.svg)](https://www.npmjs.com/package/@sentry/hub)
 [![npm dt](https://img.shields.io/npm/dt/@sentry/hub.svg)](https://www.npmjs.com/package/@sentry/hub)
 
+## Package Discontinued
+
+This package was discontinued with version 8.0.0 of the Sentry JavaScript SDKs. Instead, relevant exports from this
+package are exported from `@sentry/core`. For more information have a look at the
+[Migration Guide](https://github.com/getsentry/sentry-javascript/blob/develop/MIGRATION.md#sentryhub).
+
 ## Links
 
 - [Official SDK Docs](https://docs.sentry.io/quickstart/)

packages/integrations/README.md

@@ -15,6 +15,15 @@
 - [Official SDK Docs](https://docs.sentry.io/quickstart/)
 - [TypeDoc](http://getsentry.github.io/sentry-javascript/)
 
+## Package Discontinued
+
+This package was discontinued with version 8.0.0 of the Sentry JavaScript SDKs. All integrations from this package are
+now directly exported from the SDK packages like `@sentry/react` or `@sentry/node`. For more information have a look at
+the migration guide for
+[client-](https://docs.sentry.io/platforms/javascript/migration/v7-to-v8/#removal-of-sentryintegrations-package) and
+[server-side](https://docs.sentry.io/platforms/javascript/guides/node/migration/v7-to-v8/#removal-of-sentryintegrations-package)
+SDKs.
+
 ## General
 
 Pluggable integrations that can be used to enhance JS SDKs.