Don't show website previews for admin links

[biggianteye]

Description of the issue 📄

We have social media previews for links to the codebar website. There is a subset of links that start with /admin that are intended for managing aspects of codebar. They require you to be logged in and are therefore not for public consumption. A social media preview isn't very useful in this situation.

We should skip previews for admin urls.

As an extension to this we could also skip previews for any other pages that require logging in, but that could be handled in a separate issue.

Screenshots 📷

Steps to fix 🛠

To do 📋

• Claim this issue (comment below, or assign yourself if you are part of the codebar org)
• Fork and clone the repository
• Update the relevant files. Follow the steps to fix section in this issue.
• Commit your changes as one commit. Use the title of this issue as your commit message
• Submit a pull request
• Mention this issue in the PR description by including it's number
• Have your pull request reviewed & merged by a codebar team member