feat: add 'proof of React' challenge

Signed-off-by: Xe Iaso <me@xeiaso.net>

package-lock.json

@@ -9,7 +9,8 @@
       "version": "1.21.3",
       "license": "ISC",
       "dependencies": {
-        "@aws-crypto/sha256-js": "^5.2.0"
+        "@aws-crypto/sha256-js": "^5.2.0",
+        "preact": "^10.27.1"
       },
       "devDependencies": {
         "cssnano": "^7.1.0",
@@ -2326,6 +2327,16 @@
         "postcss": "^8.4.32"
       }
     },
+    "node_modules/preact": {
+      "version": "10.27.1",
+      "resolved": "https://registry.npmjs.org/preact/-/preact-10.27.1.tgz",
+      "integrity": "sha512-V79raXEWch/rbqoNc7nT9E4ep7lu+mI3+sBmfRD4i1M73R3WLYcCtdI0ibxGVf4eQL8ZIz2nFacqEC+rmnOORQ==",
+      "license": "MIT",
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/preact"
+      }
+    },
     "node_modules/pretty-hrtime": {
       "version": "1.0.3",
       "resolved": "https://registry.npmjs.org/pretty-hrtime/-/pretty-hrtime-1.0.3.tgz",