[Model] add Paddle.js web demo (#392)

* add application include paddle.js web demo and xcx

* cp PR #5

* add readme

* fix comments and link

* fix xcx readme

* fix Task 1

* fix bugs

* refine readme

* delete ocrxcx readme

* refine readme

* fix bugs

* delete old readme

* 200px to 300px

* revert 200px to 300px

Co-authored-by: Jason <jiangjiajun@baidu.com>

examples/application/js/mini_program/ocrdetectXcx/app.json

@@ -0,0 +1,12 @@
+{
+  "pages": [
+    "pages/index/index"
+  ],
+  "plugins": {
+    "paddlejs-plugin": {
+      "version": "2.0.1",
+      "provider": "wx7138a7bb793608c3"
+    }
+  },
+  "sitemapLocation": "sitemap.json"
+}