Replaced static links to prod UI with docs links

[validbeck]

Internal Notes for Reviewers

sc-6615

1. https://app.prod.validmind.ai/ > https://docs.validmind.ai/guide/configuration/register-with-validmind.html
2. https://app.prod.validmind.ai/model-inventory > https://docs.validmind.ai/guide/model-inventory/working-with-model-inventory.html
3. In the [Platform UI](https://app.prod.validmind.ai), go to the **Documentation** page for the model you registered earlier. > In the ValidMind Platform UI, go to the **Documentation** page for the model you registered earlier. ([Need more help?](https://docs.validmind.ai/guide/model-documentation/working-with-model-documentation.html))

[github-actions]

PR Summary

This pull request updates various Jupyter notebooks in the project to modify URLs and improve the styling of alert messages. The changes include:

1. URL Updates: The URLs pointing to the ValidMind platform have been updated to point to the documentation pages instead of the production app. This change affects links for logging in, registering, and accessing various features.
2. Styling Changes: The color of the text in alert messages has been changed from #222425 to black, and the border color has also been updated to black. Additionally, <br></br> tags have been added for better formatting.

These changes aim to improve the user experience by directing users to the appropriate documentation and enhancing the readability of alert messages.

Test Suggestions

• Verify that all updated URLs correctly point to the intended documentation pages.
• Check the formatting of the alert messages in the notebooks to ensure the new styling is applied correctly.
• Run the notebooks to ensure that there are no broken links or rendering issues.
• Ensure that the functionality of the notebooks remains unchanged apart from the URL and styling updates.

[cachafla]

Awesome 👌