Field descriptions within arrays should be aware of its index

[tyteen4a03]

It would be great if custom React components (e.g. for admin.description) used by fields within arrays can be made aware of the index of the array entry.

[JarrodMFlesch]

The description components could just take a new prop for "path" and then you would be able to determine the index from the pathname passed through. Would you like to take a crack at a PR? Would be a pretty simple one and I could lead you in the right direction some time this week.

[tyteen4a03]

Made a quick PR: #4364

[JarrodMFlesch]

Thanks! Looks great, I'll check it out on my laptop in the morning 👍