docs: update screenshot for curve demo (#3329)

Author: NewByVector

sites/x6-sites/examples/edge/connector/demo/meta.json

@@ -38,7 +38,7 @@
         "zh": "二次贝塞尔曲线",
         "en": "Quadratic Bessel Curve"
       },
-      "screenshot": "https://gw.alipayobjects.com/mdn/rms_43231b/afts/img/A*WJj5ToqfFz8AAAAAAAAAAAAAARQnAQ"
+      "screenshot": "https://mdn.alipayobjects.com/huamei_f4t1bn/afts/img/A*rQ1RT61kot8AAAAAAAAAAAAADtOHAQ/original"
     },
     {
       "filename": "wobble.ts",

sites/x6-sites/package.json

@@ -4,7 +4,7 @@
   "version": "1.6.2",
   "description": "X6 sites deployed on gh-pages",
   "scripts": {
-    "dev": "dumi dev",
+    "start": "dumi dev",
     "build": "dumi build",
     "clean": ""
   },