feat(express): add docs for proposed multer.none support

[mathewtrivett]

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• The commit message follows our guidelines: https://github.com/nestjs/docs.nestjs.com/blob/master/CONTRIBUTING.md

PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Docs
• Other... Please describe:

What is the current behavior?

Issue Number: N/A

I am implementing a feature that uses the Sendgrid Inbound Parse API. This sends the data encoded as multipart/form-data however the payload includes no files. I believe all data are sent as strings/text.

I reached for the Nest.js MulterModule but it currently does not support multer's none option. multer.none parses only the text fields in the body and raises an exception if any files are submitted.

What is the new behavior?

There is a PR on the main nest project that introduces a new NoFilesInterceptor as part of the MulterModule. This PR is the documentation counterpart to this proposed addition. nestjs/nest#11667

Does this PR introduce a breaking change?

• Yes
• No

Other information