refactor: Update README.md

Author: dwqs

README.md

@@ -107,6 +107,7 @@ npm i babel-plugin-on-demand-import -D
 Then add it to your `.babelrc`: 
 
 ```
+// v2
 {
     // ...
     "plugins": [
@@ -115,6 +116,17 @@ Then add it to your `.babelrc`:
         }]
     ]
 }
+
+// v3
+{
+    // ...
+    "plugins": [
+        ["on-demand-import" {
+            "libraryName": "v2-datepicker",
+            "libraryName": "lib/components"
+        }]
+    ]
+}
 ```
 
 ```

README_CN.md

@@ -106,6 +106,7 @@ npm i babel-plugin-on-demand-import -D
 修改 `.babelrc`: 
 
 ```
+// v2
 {
     // ...
     "plugins": [
@@ -114,6 +115,17 @@ npm i babel-plugin-on-demand-import -D
         }]
     ]
 }
+
+// v3
+{
+    // ...
+    "plugins": [
+        ["on-demand-import" {
+            "libraryName": "v2-datepicker",
+            "libraryName": "lib/components"
+        }]
+    ]
+}
 ```
 
 ```