docs: Add v5 upgrade docs

[paulhibbitts]

Summary

Related issue, if any:

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation content changes
• Other (please describe):

For any code change,

• Related documentation has been updated, if needed
• Related tests have been added or updated, if needed

Does this PR introduce a breaking change?

• Yes
• No

Tested in the following browsers:

• Chrome
• Firefox
• Safari
• Edge

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[paulhibbitts]

Made PR update re: v4 CSS customizations may need to be changed, as suggested by @trusktr. All set to go if no more suggested changes.

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Project	Deployment	Review	Updated (UTC)
docsify-preview	Ready	Preview, Comment	Jan 13, 2026 2:26am

[paulhibbitts]

Thanks for your suggestions @sy-records , I've committed all of them and as well the extra note re: Vue visual styling, 🙏🏻 If you can make a new PR Preview I can then share on Discord for any final community feedback etc.