feat: Adds automatic thread scaling at runtime and php_ini configuration in Caddyfile (#1266)

Adds option to scale threads at runtime

Adds php_ini configuration in Caddyfile

testdata/performance/database.js

@@ -0,0 +1,30 @@
+import http from 'k6/http'
+
+/**
+ * Modern databases tend to have latencies in the single-digit milliseconds.
+ * We'll simulate 1-10ms latencies and 1-2 queries per request.
+ */
+export const options = {
+  stages: [
+    { duration: '20s', target: 100 },
+    { duration: '30s', target: 200 },
+    { duration: '10s', target: 0 }
+  ],
+  thresholds: {
+    http_req_failed: ['rate<0.01']
+  }
+}
+
+/* global __ENV */
+export default function () {
+  // 1-10ms latency
+  const latency = Math.floor(Math.random() * 10) + 1
+  // 1-2 iterations per request
+  const iterations = Math.floor(Math.random() * 2) + 1
+  // 1-30000 work units per iteration
+  const work = Math.ceil(Math.random() * 30000)
+  // 1-40 output units
+  const output = Math.ceil(Math.random() * 40)
+
+  http.get(http.url`${__ENV.CADDY_HOSTNAME}/sleep.php?sleep=${latency}&work=${work}&output=${output}&iterations=${iterations}`)
+}