docs(web-modeler): document file download and export options

[jfriedenstab]

Description

Documents the file download and export options in Web Modeler.

Part of https://github.com/camunda/product-hub/issues/1959.
Closes https://github.com/camunda/web-modeler/issues/5286.

When should this change go live?

• This change is not yet live and should not be merged until Feb 13 (8.5.0-alpha1 release date) (apply hold label or convert to draft PR)?
• There is no urgency with this change.
• This change or page is part of a marketing blog, conference talk, or something else on a schedule.
• This functionality is already available but undocumented.
• This is a bug fix or security concern.

PR Checklist

• I have added changes to the relevant /versioned_docs directory, or they are not for an already released version.
• I have added changes to the main /docs directory (aka /next/), or they are not for future versions.
• My changes require an Engineering review, and I've assigned an engineering manager or tech lead as a reviewer, or my changes do not require an Engineering review.
• My changes require a technical writer review, and I've assigned @christinaausley as a reviewer, or my changes do not require a technical writer review.

[github-actions]

👋 🤖 🤔 Hello! Did you make your changes in all the right places?

These files were changed only in docs/. You might want to duplicate these changes in versioned_docs/version-8.4/.

• docs/components/modeler/web-modeler/file-download.md
• docs/components/modeler/web-modeler/img/download/download-bpmn.png
• docs/components/modeler/web-modeler/img/download/download-connector-template.png
• docs/components/modeler/web-modeler/img/download/download-dmn.png
• docs/components/modeler/web-modeler/img/download/download-form.png
• docs/components/modeler/web-modeler/img/download/multi-file-download.png
• docs/components/modeler/web-modeler/img/download/single-file-download.png

You may have done this intentionally, but we wanted to point it out in case you didn't. You can read more about the versioning within our docs in our documentation guidelines.

[HanselIdes]

Overall LGTM - I suggested some ways to clarify the value and shorten the text. Overall, the UI for this kind of feature should be self-explanatory enough that documentation can be light. The main 'gotchas' were covered nicely: the download limit and different behavior between project view and file editor view.

You do not need to re-request my review.

[jfriedenstab]

Thanks @HanselIdes! 👍🏻 I've adopted your suggestions.

[christinaausley]

Nice writing here!

[jfriedenstab]

@HanselIdes To allow me to merge the PR, I think you need to approve it (because you requested changes).

adjusted in commit