Add Ko-fi icon (#869)

* Add Ko-fi icon

Add icon for Ko-fi, a service similar to Patreon, only without recurring
donations. Icon is based on the SVG found on their About page (https://ko-fi.com/home/about).

* Add Ko-fi details

Update the simple-icons.json file to include Ko-fi. The source links to
the page where the SVG was found, the color is taken from this SVG.

* Fix indentation for Ko-fi data

_data/simple-icons.json

@@ -915,6 +915,11 @@
             "hex": "00B057",
             "source": "https://koding.com/About"
         },
+        {
+            "title": "Ko-fi",
+            "hex": "F16061",
+            "source": "https://ko-fi.com/home/about"
+        },
         {
             "title": "Lanyrd",
             "hex": "3C80CA",

icons/kofi.svg

@@ -0,0 +1 @@
+<svg aria-labelledby="simpleicons-ko-fi-icon" role="img" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><title id="simpleicons-ko-fi-icon">Ko-fi icon</title><path d="M23.881 8.948c-.773-4.085-4.859-4.593-4.859-4.593H.723c-.604 0-.679.798-.679.798s-.082 7.324-.022 11.822c.164 2.424 2.586 2.672 2.586 2.672s8.267-.023 11.966-.049c2.438-.426 2.683-2.566 2.658-3.734 4.352.24 7.422-2.831 6.649-6.916zm-11.062 3.511c-1.246 1.453-4.011 3.976-4.011 3.976s-.121.119-.31.023c-.076-.057-.108-.09-.108-.09-.443-.441-3.368-3.049-4.034-3.954-.709-.965-1.041-2.7-.091-3.71.951-1.01 3.005-1.086 4.363.407 0 0 1.565-1.782 3.468-.963 1.904.82 1.832 3.011.723 4.311zm6.173.478c-.928.116-1.682.028-1.682.028V7.284h1.77s1.971.551 1.971 2.638c0 1.913-.985 2.667-2.059 3.015z"/></svg>