feat: add StandaloneActivity sample

README.md

@@ -121,6 +121,8 @@ The following samples demonstrate much of the basic functionality and capabiliti
 
 - **[SimpleActivity](https://github.com/temporalio/samples-php/tree/master/app/src/SimpleActivity)**: Single Activity Workflow
 
+- **[StandaloneActivity](https://github.com/temporalio/samples-php/tree/master/app/src/StandaloneActivity)**: How to execute an Activity without a Workflow
+
 - **[ActivityRetry](https://github.com/temporalio/samples-php/blob/master/app/src/ActivityRetry)**: How to retry an Activity
 
 - **[AsyncActivity](https://github.com/temporalio/samples-php/blob/master/app/src/AsyncActivity)**: How to call Activities asynchronously and wait for them using Promises

app/composer.json

@@ -1,9 +1,15 @@
 {
   "minimum-stability": "dev",
   "prefer-stable": true,
+  "repositories": [
+    {
+      "type": "vcs",
+      "url": "https://github.com/temporalio/sdk-php"
+    }
+  ],
   "require": {
     "spiral/tokenizer": "^3.16.0",
-    "temporal/sdk": "^2.17",
+    "temporal/sdk": "dev-feature/standalone-activities as 2.21.0",
     "temporal/open-telemetry-interceptors": "^1.0",
     "open-telemetry/exporter-otlp": "^1.3",
     "open-telemetry/transport-grpc": "^1.1",