Add transparency information to social preview docs

[aisgbnok]

Why:

Closes #16417

What's being changed:

Addition of a small "Transparency" section to the "Customizing your repository's social media preview" page.

Here is what the built and rendered addition looks like:

If you have any feedback, questions, concerns, etc. don't hesitate to reply. I can add more information. For example, here is what a social preview with a transparent PNG looks like in Google Chat/Spaces.

Check off the following:

• I have reviewed my changes in staging (look for "Automatically generated comment" and click Modified to view your latest changes).
• For content changes, I have completed the self-review checklist.

Writer impact (This section is for GitHub staff members only):

• This pull request impacts the contribution experience
  • I have added the 'writer impact' label
  • I have added a description and/or a video demo of the changes below (e.g. a "before and after video")

[welcome]

Thanks for opening this pull request! A GitHub docs team member should be by to give feedback soon. In the meantime, please check out the contributing guidelines.

[github-actions]

Automatically generated comment ℹ️

This comment is automatically generated and will be overwritten every time changes are committed to this branch.

The table contains an overview of files in the content directory that have been changed in this pull request. It's provided to make it easy to review your changes on the staging site. Please note that changes to the data directory will not show up in this table.

---

Content directory changes

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Source	Preview	Production	What Changed
content/repositories/managing-your-repositorys-settings-and-features/customizing-your-repository/customizing-your-repositorys-social-media-preview.md	Modified	Original

[ramyaparimi]

@aisgbnok
Thanks so much for opening a PR! I'll get this triaged for review ⚡

[mchammer01]

@aisgbnok 👋🏻 - thank you for your contribution ✨
I've made some suggestions (most of them relating to our content model) that I'm going to apply.
I'll merge this once I've checked that the preview works fine 🚢

[mchammer01]

@ramyaparimi 👋🏻 - I think this is ready to be merged. The deployment is behaving oddly and I can't see the View deployment button, nor the updates I've just made on the preview. I raised this yesterday with the team in charge but haven't heard anything back.

[aisgbnok]

@mchammer01 Hey, the preview link seems to be updated for me?

I like your changes, writing documentation can be hard. It takes a certain mindset. My only concern is that **Tip** doesn't look right? Thanks! ☺️

[mchammer01]

@aisgbnok - yes, thanks, I noticed that the preview eventually got updated but things are a bit slow today 😟
I'll see if I can fix the rendering on the tip 🙂

[mchammer01]

I fixed the other tip too and hopefully we should be good to go. Thanks for highlighting the rendering issue @aisgbnok ✨
Just waiting for an updates preview.

[mchammer01]

I've marked this as ready-to-merge but one of the tests is failing. Re-running it.

[ramyaparimi]

@mchammer01 Since this test is still failing, I will wait until the test is passing to merge this PR 💖. I am not entirely sure why the test is failing though, is there anything I can do to fix the error?

[aisgbnok]

I'm not sure. Is there something wrong with the image I committed? Any specific format I should be using. It looks fine on the preview. The error seems to be Error: Input required and not supplied: token which doesn't seem related, but I'm unsure. It would be great if all checks passed.

[mchammer01]

@ramyaparimi - I think we need someone from engineering to take a look. I'ts token-related and I haven't got a clue.
The Optimize images job optimizes the size of screenshots in our docs, and may resize them before committing.

[ramyaparimi]

@aisgbnok That is what I thought as well that it could be the size of the image or a format error. But seems like it is something related to an input. I will ask my team about the error and get back to you 💖.

[heiskr]

Looks like we can't write to forks using GitHub Actions. I've disabled the optimize images for the public repo. If possible to optimize the image before we merge that would be great, but disabling for the public repo should be enough to get the build green.

[ramyaparimi]

@mchammer01 I will wait for your one final approval before I can get this merged 💖.

[mchammer01]

Final approval, as requested 😄

[aisgbnok]

@heiskr I tried to run optimize images from my repo, but it skipped. I think because https://github.com/aisgbnok/docs/blob/db6301e9381d28fb1576cd4ac606d01f878529c3/.github/workflows/optimize-images.yml#L19

https://github.com/aisgbnok/docs/actions/runs/2097447192

Not sure if there is another way, or if I should just leave it be? Thanks for the help!

[heiskr]

No worries, we can always run it later 🤷🏼

[github-actions]

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