Add Healthcheck; Search missing immediately (#36)

cmd/healthcheck/main.go

@@ -0,0 +1,22 @@
+package main
+
+import (
+	"cmp"
+	"net/http"
+	"os"
+)
+
+func main() {
+	port := cmp.Or(os.Getenv("QBIT_PORT"), "8282")
+	resp, err := http.Get("http://localhost:" + port + "/api/v2/app/version")
+	if err != nil {
+		os.Exit(1)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		os.Exit(1)
+	}
+
+	os.Exit(0)
+}