docs: add Access Manager categories snippets

docs-snippets/access_manager.rb

@@ -0,0 +1,49 @@
+require 'pubnub'
+
+pubnub = Pubnub.new(
+  subscribe_key: 'demo',
+  publish_key: 'demo',
+  secret_key: 'demo',
+  user_id: 'myUniqueUserId'
+)
+
+# snippet.grantTokenWithCategories
+# Grants `my-authorized-user-id` permission to list all channel metadata and all uuid metadata.
+# Category permissions support only the `get` operation.
+envelope = pubnub.grant_token(
+  ttl: 15,
+  authorized_user_id: 'my-authorized-user-id',
+  categories: {
+    channels: Pubnub::Permissions.cat(get: true),
+    uuids: Pubnub::Permissions.cat(get: true)
+  },
+  http_sync: true
+)
+
+puts envelope.result[:data][:token]
+# snippet.end
+
+# snippet.parseTokenWithCategories
+# Decodes a token that was granted with category permissions.
+# The `cat` section holds the permission bitmask for each category: `chan` for channel
+# metadata and `uuid` for uuid metadata. The `get` permission has the value 32.
+parsed_token = pubnub.parse_token('use-token-string-generated-by-grant_token')
+
+categories = parsed_token['cat']
+puts "Channel metadata category: #{categories['chan']}"
+puts "Uuid metadata category: #{categories['uuid']}"
+# snippet.end
+
+# snippet.grantWithCategories
+# Grants the auth key permission to list all channel metadata and all uuid metadata.
+# This legacy `grant` method requires the secret key to be set on the client.
+envelope = pubnub.grant(
+  categories: %w[channels uuids],
+  auth_key: 'my-auth-key',
+  get: true,
+  ttl: 15,
+  http_sync: true
+)
+
+puts envelope.status
+# snippet.end