[#XX] Hello world contract

Created a contract to test neo-go contract init command.
It compiles just fine.

Signed-off-by: Lebedeva Ekaterina <ekaterina.lebedeva@yadro.com>

FirstContract/go.mod

@@ -0,0 +1,5 @@
+module FirstContract
+
+go 1.20
+
+require github.com/nspcc-dev/neo-go/pkg/interop v0.0.0-20221202075445-cb5c18dc73eb

FirstContract/go.sum

@@ -0,0 +1,2 @@
+github.com/nspcc-dev/neo-go/pkg/interop v0.0.0-20221202075445-cb5c18dc73eb h1:GFxfkpXEYAbMIr69JpKOsQWeLOaGrd49HNAor8uDW+A=
+github.com/nspcc-dev/neo-go/pkg/interop v0.0.0-20221202075445-cb5c18dc73eb/go.mod h1:23bBw0v6pBYcrWs8CBEEDIEDJNbcFoIh8pGGcf2Vv8s=

FirstContract/main.go

@@ -0,0 +1,15 @@
+package FirstContract
+
+import "github.com/nspcc-dev/neo-go/pkg/interop/runtime"
+
+var notificationName string
+
+// init initializes notificationName before calling any other smart-contract method
+func init() {
+	notificationName = "Hello world!"
+}
+
+// RuntimeNotify sends runtime notification with "Hello world!" name
+func RuntimeNotify(args []interface{}) {
+    runtime.Notify(notificationName, args)
+}

FirstContract/neo-go.yml

@@ -0,0 +1,11 @@
+name: FirstContract
+sourceurl: http://example.com/
+safemethods: []
+supportedstandards: []
+events:
+    - name: Hello world!
+      parameters:
+        - name: args
+          type: Array
+permissions:
+    - methods: '*'