Update Claiming Issue "to wait until a project is assigned to you"

[kjaymiller]

TLDR

We need to update the replacing the wait for +1 and replace with "Wait for the issue to be assigned to you"

Currently the CONTRIBUTING.md says to wait for a thumbs up (👍🏾). This can be confusing because anyone can give a thumbs up. Ultimately the issue should be assigned to you.

[drakeredwind01]

I'm already working on something else for CONTRIBUTING.md
I can add this to the file i'm already working on.