feat(attribution): add react flow attribution

src/style.css

@@ -144,8 +144,8 @@
 .react-flow__controls {
   position: absolute;
   z-index: 5;
-  bottom: 10px;
-  left: 10px;
+  bottom: 20px;
+  left: 15px;
 
   &-button {
     width: 24px;
@@ -161,6 +161,41 @@
 .react-flow__minimap {
   position: absolute;
   z-index: 5;
-  bottom: 10px;
-  right: 10px;
+  bottom: 20px;
+  right: 15px;
+}
+
+.react-flow__attribution {
+  font-size: 10px;
+  position: absolute;
+  z-index: 1000;
+  background: rgba(255, 255, 255, 0.5);
+  padding: 2px 3px;
+  color: #999;
+
+  a {
+    color: #555;
+    text-decoration: none;
+  }
+
+  &.top {
+    top: 0;
+  }
+
+  &.bottom {
+    bottom: 0;
+  }
+
+  &.left {
+    left: 0;
+  }
+
+  &.right {
+    right: 0;
+  }
+
+  &.center {
+    left: 50%;
+    transform: translateX(-50%);
+  }
 }