Add image license metadata

Author: ciembor

about/index.html

@@ -46,6 +46,9 @@
           "width": 1280,
           "height": 712,
           "caption": "4bit Terminal Color Scheme Designer interface",
+          "license": "https://creativecommons.org/licenses/by/4.0/",
+          "copyrightNotice": "Copyright 2026 Maciej Ciemborowicz. Licensed under Creative Commons Attribution 4.0 International.",
+          "acquireLicensePage": "https://ciembor.github.io/4bit/about/",
           "creator": {
             "@type": "Person",
             "name": "Maciej Ciemborowicz"
@@ -68,7 +71,10 @@
             "contentUrl": "https://ciembor.github.io/4bit/images/4bit-terminal-color-scheme-designer.jpg",
             "width": 1280,
             "height": 712,
-            "caption": "4bit Terminal Color Scheme Designer interface"
+            "caption": "4bit Terminal Color Scheme Designer interface",
+            "license": "https://creativecommons.org/licenses/by/4.0/",
+            "copyrightNotice": "Copyright 2026 Maciej Ciemborowicz. Licensed under Creative Commons Attribution 4.0 International.",
+            "acquireLicensePage": "https://ciembor.github.io/4bit/about/"
           },
           "description": "A free web app for creating consistent terminal color schemes and exporting terminal themes for popular terminal emulators.",
           "author": {