Add boolean for volunteers needed, then fix data

[sya]

When creating a new Shelters record

When creating a new Needs record (this is written as if someone should answer with a Yes/No rather than provide additional details)

[ironcoconut]

This is a hold over from the Google sheets and will remain for now. The fix is not straightforward even though it would seem to be.

[jwo]

Way forward:

• Add new field to store the volunteers needed (default false)
• populate the field (manually)
• remove field when complete

If someone is willing to shepherd the data, I can make the tech work.

@sya Let me know, either here or in slack, if you or someone else can run with the data part of the project.