faq: explain how to add records to a community

[slint]

There are two use-cases:

• New records that can be directly uploaded to the community (via navigating to the community's page and clicking the "Upload" button)
• Records already published, that have to be edited and communities have to be specified in the upload form.

[carlinmack]

Can be closed?

https://help.zenodo.org/docs/share/submit-for-review/
https://help.zenodo.org/docs/share/submit-to-community/