[Docs] OG image is not working as expected

[marufshidiq]

Describe the bug
I tried to share the documentation link to social media, and found that the og image did not work properly.

next-forge version
5.0.2

To Reproduce
Steps to reproduce the behavior:

1. Go to https://www.opengraph.xyz/
2. Enter any documentation link, e.g. "https://www.next-forge.com/apps/app"
3. Check the Preview section and you can see that the og image is missing

Expected behavior
When we check the homepage url, the og image is working like expected

Screenshots
This is the sample of the preview

Describe the solution you'd like

1. Simply change the code at docs/app/[[...slug]]/page.tsx from using dynamic og image to opengraph-image.png
2. Implement @vercel/og to generate dynamic og image