Add PhotoShelter

src/apps.json

@@ -12480,6 +12480,22 @@
       "script": "/particles(?:\\.min)?\\.js",
       "website": "https://vincentgarreau.com/particles.js/"
     },
+    "PhotoShelter": {
+      "cats": [
+        1
+      ],
+      "html": [
+        "<!--\\s+#+ Powered by the PhotoShelter Beam platform",
+        "<link rel=[\"']dns-prefetch[\"'] [^>]+photoshelter.com"
+      ],
+      "implies": [
+        "PHP",
+        "MySQL",
+        "jQuery"
+      ],
+      "icon": "PhotoShelter.png",
+      "website": "https://www.photoshelter.com"
+    },
     "phpAlbum": {
       "cats": [
         7