Remove sourcegraph.com links to notebooks (#875)

<!-- Explain the changes introduced in your PR -->

## Pull Request approval

You will need to get your PR approved by at least one member of the
Sourcegraph team. For reviews of docs formatting, styles, and component
usage, please tag the docs team via the #docs Slack channel.

Author: jdorfman

docs/notebooks/index.mdx

@@ -1,7 +1,7 @@
 # Notebooks
-Notebooks enable powerful live–and persistent–documentation, shareable with your organization or the world. As of release 3.39, Notebooks are Generally Available (GA). If you're a Sourcegraph enterprise user and are on version 3.39 or later, you'll find Notebooks in the header navigation, or by going to `https://<your-internal-sourcegraph-url>/notebooks`. You can also explore [public notebooks on Sourcegraph.com](https://sourcegraph.com/notebooks).
+Notebooks enable powerful live–and persistent–documentation, shareable with your organization or the world. As of release 3.39, Notebooks are Generally Available (GA). If you're a Sourcegraph enterprise user and are on version 3.39 or later, you'll find Notebooks in the header navigation, or by going to `https://<your-internal-sourcegraph-url>/notebooks`.
 
-Inspired by Jupyter Notebooks and powered by Markdown and Sourcegraph's code search, Notebooks let you and your team create living documentation that interacts directly with your code. You can leverage Notebooks to onboard a new teammate, document [known vulnerabilities](https://sourcegraph.com/notebooks/Tm90ZWJvb2s6MQ==), a [common pattern](https://sourcegraph.com/notebooks/Tm90ZWJvb2s6OTI=) in your codebase, or [useful Sourcegraph queries](https://sourcegraph.com/notebooks/Tm90ZWJvb2s6MTU=).
+Inspired by Jupyter Notebooks and powered by Markdown and Sourcegraph's code search, Notebooks let you and your team create living documentation that interacts directly with your code. You can leverage Notebooks to onboard a new teammate, document known vulnerabilities, a common pattern in your codebase, or useful Sourcegraph queries.
 
 ![](https://storage.googleapis.com/sourcegraph-assets/docs/images/notebooks/notebooks_home.gif)