fix: add close modal to keyboard navigation

client/src/components/Donation/Donation.css

@@ -217,6 +217,11 @@ li.disabled > a {
   font-size: 1.5rem;
 }
 
+.donation-modal .btn-link:focus {
+  outline-width: 1px;
+  outline-style: solid;
+}
+
 @media screen and (max-width: 991px) {
   .donation-icon-container {
     margin: 30px;

client/src/components/Donation/components/DonationModal.js

@@ -107,6 +107,7 @@ function DonateModal({ show, block, isBlockDonation, closeDonationModal }) {
               bsStyle='primary'
               className='btn-link'
               onClick={closeDonationModal}
+              tabIndex='0'
             >
               {closeLabel ? 'Close.' : 'Ask me later.'}
             </Button>