[README] Add GitPOAP Badge to Display Number of Minted GitPOAPs for Contributors

[kayla-henrie]

Changes:

Hey all, this PR adds a GitPOAP Badge to the README that displays the number of minted GitPOAPs for this repository by contributors to this repo.

You can see an example of this in our Documentation repository.

This should help would-be contributors as well as existing contributors find out that they will/have received GitPOAPs for their contributions.

CC: @colfax23 @kayla-henrie

Types of changes

What types of changes does your code introduce?
Put an x in the boxes that apply

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Other (please describe): see above

Testing

Requires testing

• Yes
• No

In case you checked yes, did you write tests??

• Yes
• No

[LukaszRozmej]

Can you make it bigger to be same size as our other items