documentation: Increase block width in help center.

[Joelute]

After merging #24352, we want to increase the block width in the help center to reduce the amount of scrollbars that are shown.

CZO discussion

Screenshots and screen captures: In CZO discussion

Self-review checklist

• [x] Self-reviewed the changes for clarity and maintainability (variable names, code reuse, readability, etc.).

Communicate decisions, questions, and potential concerns.

• [ ] Explains differences from previous plans (e.g., issue description).
• [ ] Highlights technical choices and bugs encountered.
• [ ] Calls out remaining decisions and concerns.
• [ ] Automated tests verify logic where appropriate.

Individual commits are ready for review (see commit discipline).

• [ ] Each commit is a coherent idea.
• [ ] Commit message(s) explain reasoning and motivation for changes.

Completed manual review and testing of the following:

• [x] Visual appearance of the changes.
• [ ] Responsiveness and internationalization.
• [ ] Strings and tooltips.
• [ ] End-to-end functionality of buttons, interactions and flows.
• [ ] Corner cases, error conditions, and easily imagined bugs.

[alya]

Continuing discussion on CZO.

[timabbott]

The commit message probably needs an update now that this changes the other width too. (Or maybe that should be a second commit with its own commit message; either way works).

Also, when you update a PR, always post a comment on the PR with what you changed and why, possibly linking a chat.zulip.org thread with more context. Half the time reviewers come across an active PR from GitHub, not Zulip, and it's really helpful if the PR thread always explains the author's latest understanding of the work and its state.

[Joelute]

Oh yeah, I completely forgot about that, sorry. I guess I'll sperate them into two commits to just help with organization and readability. I'll try to post a comment on the PR explaining each commit changes from now on. For now I'll just update the commit messages and the PR description.

[timabbott]

Merged, thanks @Joelute!

I didn't bother changing it before merging this, but generally we avoid links to chat.zulip.org threads in commit messages -- they don't render well in Git in a terminal, but the main reason is that it's a poor substitute for having a clearly written, self-contained summary of the conclusion of the discussion in the commit message than a link (which one can usually find via the PR).

(I think also your line-wrapping for commit message paragraphs is a little overly aggressive)

[Joelute]

Yeah, I wanted to test if linking would render well but it seems not. I generally wrap when the commit message is as long as the header so it was overly aggressive on this one. I think I should try and configure the editor to automatically wrap text to 70 or fewer columns per line instead of manually wrapping.