Duplicate Pages - Installing DevBox, GitHub Actions

[seanpoulter]

There are two pairs of duplicate pages:

• docs/devbox/installing-devbox/index.mdx (imported, no tabs)
• docs/devbox/installing-devbox.mdx (recently updated to use tabs)

and

• docs/devbox/continuous-integration/github-action/index.mdx
• docs/devbox/continuous-integration/github-action.mdx

Please confirm which should serve as the source of truth and we can update accordingly.

Edit: My suggestion is to keep the first pages and pull the changes there. They follow the same convention as all the others.