docs: add optional sha256sums

58.md

@@ -20,6 +20,8 @@ The `image` field is the URL of a high-resolution image representing the badge.
 
 The `thumbs` field is an object containing thumbnail versions of the image referenced in the `image` field. The format of the keys are the dimensions `width`x`height` in pixels and the value is an URL pointing to respective thumbnail image.
 
+The `sha256sums` field is an object containing the fields `image` and one for every thumbnail in the `thumbs` object with the same key. The values are the SHA256 digests of each one of image files.
+
 ### Profile Badges Event
 
 The number of badges a pubkey can receive is unbounded. The Profile Badge event allows individual users to choose
@@ -67,7 +69,16 @@ Clients SHOULD render the most appropriate badge thumbnail according to the numb
       \"128x128\": \"https://relay.nostr/badges/two-year-club-128x128.png\",
       \"64x64\": \"https://relay.nostr/badges/two-year-club-64x64.png\",
       \"32x32\": \"https://relay.nostr/badges/two-year-club-32x32.png\",
-      \"16x16\": \"https://relay.nostr/badges/two-year-club-16x16.png\",
+      \"16x16\": \"https://relay.nostr/badges/two-year-club-16x16.png\"
+    },
+    \"sha256sums\": {
+      \"image\": \"8d43b3081c8091147e03e41878604606c8aa53d1337d49a4d5e0e8c29c223798\",
+      \"512x512\": \"af94c2afee5321b6acbca7ba00fcfa4ae2e103dda3a3a038e8b0aec4207ef164\",
+      \"256x256\": \"8c1eaf36d0353e20e30511c473411f1df0b9e58f68daadad972a8a6955824a0e\",
+      \"128x128\": \"86b0ebe1cf924f39a0eb4cfde5cdfe8a271b882284fc4f1c353bf6589eef1870\",
+      \"64x64\": \"a92ec141189c8e0228d8c388b9c0e822ecf1347367b834c43c7e82427569e06d\",
+      \"32x32\": \"6afa09c719f0729253ce8034618743d3a3aadd7aa4215554b7e5aa72b46c41a9\",
+      \"16x16\": \"abacf2675c05b7710cf853800a95e4191c10b2005540a39adb4b7cdda617249b\"
     }
   }",
   ...other fields...