Add an example page with automatically generated asciinema record

[hyrodium]

This PR adds an exanple page generation with asciinema.

https://user-images.githubusercontent.com/7488140/230780568-4d9ebee8-b3ae-455f-a6aa-03e2f74fbd98.mp4

[hyrodium]

Here's an example of uploaded asciicast from the GitHub Action: https://asciinema.org/a/Lvnh0Zl32nYyHHau336pq13Ko I'm not sure we have a way to change the username runner in the webpage to something like Replay.jl.

[hyrodium]

Oh, I just noticed that non-authorized uploaded casts may be removed from the asciinema server. https://blog.asciinema.org/post/archival/

We can avoid removals by adding the install ID in the output of asciinema auth, but I'm not sure:

• Whether the output should be treated as secret.
  • If so, how can we get the ID from the action?
• Is the ID always different for each action workflow?
  • If so, is there any limitation on the number of registered ID?
  • If not, how can we distinguish casts uploaded from GitHub Actions in other repos?

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EDIT: updates on the above.

Whether the output should be treated as secret.

It should be because a person who knows the id can delete the uploaded casts.

If so, how can we get the ID from the action?

Posting the ID to some external services such as slack or e-mail would be a good choice. Is it annoying to have to set an ID for every document build? If it bothers you, we can collaboratively manage a new asciinema account.

Is the ID always different for each action workflow?

It seems the IDs are always different. I have checked that on https://github.com/hyrodium/Replay.jl/pull/2.

If so, is there any limitation on the number of registered ID?

At least, I could not find that kind of limitation on https://github.com/asciinema/asciinema-server.

[terasakisatoshi]

non-authorized uploaded casts may be removed from the asciinema server.

Oh yeah, I totally forgot. 😅 . I remembered the reason why I did not add examples generated by asciinema to docs.

We can avoid removals by adding the install ID in the output of asciinema auth, but I'm not sure:

There is a workaround: Use standalone player bundle in your HTML page

[terasakisatoshi]

This PR is a very good contribution to the repository. It would be a shame to dismiss this pull request. I'd like to merge this pull request and then figure out what to do with it later.

[terasakisatoshi]

done is better than perfect.(ドーンだよ！https://www.youtube.com/watch?v=Ywq4XR0G4Qk&t=15s ）