V16 CMS: Tell the developer to set MaxRequestLength regardless of hosting platform

[iOvergaard]

📋 Description

The intention of this pull request is to inform the reader, that it is advisable to set the MaxRequestLength in appsettings.json regardless of hosting platform, as Umbraco 16 uses this value to evaluate the validation for file uploads. (So instead of guessing the maximum file size, it will actively guide/advise the user that they are exceeding the file size).

📎 Related Issues (if applicable)

✅ Contributor Checklist

I've followed the Umbraco Documentation Style Guide and can confirm that:

• Code blocks are correctly formatted.
• Sentences are short and clear (preferably under 25 words).
• Passive voice and first-person language (“we”, “I”) are avoided.
• Relevant pages are linked.
• All links work and point to the correct resources.
• Screenshots or diagrams are included if useful.
• Any code examples or instructions have been tested.
• Typos, broken links, and broken images are fixed.

Product & Version (if relevant)

16

Deadline (if relevant)

ASAP

📚 Helpful Resources

• 🧾 Umbraco Contribution Guidelines
• ✍️ Umbraco Documentation Style Guide