Add option to open links in new tab (seems simple, it probably already exists, but I don't know how to do it)

[firmai]

Bug description

Recent changes to GitBook have modified link behavior, causing all links to open in the same tab. This creates significant complications when GitBook documents are embedded as iFrames in other websites, as security rules may prevent external links from displaying properly.

This issue affects user experience, workflow, and the functionality of GitBook content when embedded in other platforms. Users are unable to access external links when the content is embedded, disrupting information flow and reducing the utility of GitBook documentation.

How to reproduce

1. Embed a GitBook document containing external links into another website using an iFrame.
2. Navigate to the embedded GitBook content on the website.
3. Attempt to click on an external link within the GitBook content.
4. Observe that instead of opening in a new tab, the link either fails to load or displays a connection error due to security restrictions.

Additional context

• This issue particularly impacts organizations and users who frequently embed GitBook content in their own websites or platforms.
• The previous behavior of opening links in new tabs was more compatible with embedded scenarios and aligned with common web conventions.
• A configurable option to choose between opening links in the current tab or a new tab would resolve this issue while maintaining flexibility for different use cases.
• This bug significantly impacts the usability and effectiveness of GitBook as a documentation platform, especially in scenarios where content needs to be integrated with other systems.

Edit: I am using the deployed paid version