doc(ja): translate 404 page into Japanese

[Gumichocopengin8]

Summary

Partial work of #880. 404 page

Test Plan

I made an issue withastro/starlight#1154 about 404 page in starlight issue since 404 page is a special case. Looks like what we need to do to show 404 page is that make ja/404.md and setup vercel.json. Not 100% sure if this would work so if we have the website preview, we should def check it out.

[nissy-dev]

Thank you for your contribution and investigating the problem!

If there is some problems, I think there is no need to translate 404.md.
I'm very sorry, but I'll close this PR and update task list in #880.

[Gumichocopengin8]

ok sure, but 404 page already has the issue https://biomejs.dev/fdsa (this page isn't a valid page so we expect to see 404 page, but not really). This PR might potentially fix the issue. Im fine with closing this PR anyways!

[nissy-dev]

ok sure, but 404 page already has the issue https://biomejs.dev/fdsa (this page isn't a valid page so we expect to see 404 page, but not really).

Oh, I see. First, I try to check your vercel.json. If the PR is from a forked repository, preview-deploy job will not fire...

[Gumichocopengin8]

ok sure, but 404 page already has the issue https://biomejs.dev/fdsa (this page isn't a valid page so we expect to see 404 page, but not really).

Oh, I see. First, I try to check your vercel.json. If the PR is from a forked repository, preview-deploy job will not fire...

Got it. we can close this PR and you or other core member can make a PR with the code, then we see the website preview. What do you think?

[nissy-dev]

we can close this PR and you or other core member can make a PR with the code, then we see the website preview. What do you think?

I did in #956 And I don't know why, but the preview-deploy job ran in this PR, so I think we can confirm.

[nissy-dev]

It looks like the deployment is failing, can you confirm?

[Gumichocopengin8]

yeah looks like vercel.json pattern is not correct. could you try with https://github.com/withastro/starlight/blob/8d88850c64928878dc7d63c3ec90756690da8387/docs/vercel.json#L20 which is suggested in this comment? I replace routes with rewrite cuz routes is not recommended anymore but for the testing purpose, we can use that one. Let me also push the new commit here in case the CI works.

[Gumichocopengin8]

also, I'm not sure what is the right form to write vercel.json specifically for Starlight. I asked a question about this. until we get a response, we might need to try several times. If you or other contributors think it's not worth it, I dont mind skipping this task.

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PS: looks like Ci is not working from the forked repo as you said. CI worked cuz of your PR I guess?

[nissy-dev]

also, I'm not sure what is the right form to write vercel.json specifically for Starlight. I asked a question about this. until we get a response, we might need to try several times. If you or other contributors think it's not worth it, I dont mind skipping this task.

I think your work is valuable, but I would appreciate it if you could confirm preview-deploy job works well in a forked repository before submitting a PR. I don't want to spend much time debugging in this PR, so I'll close this PR.