Add locale to Opts type (#412)

* Add locale to Opts type

as available in echarts v5

* Add example of using Opts.locale to the demo website

Co-authored-by: Sylvain Thénault <sylvain.thenault@lowatt.fr>

Author: sthenault

docs/examples/locale.md

@@ -0,0 +1,49 @@
+---
+title: Locale
+order: 8
+---
+
+## Locale
+
+```tsx
+import React from 'react';
+import ReactECharts from 'echarts-for-react';
+
+import "echarts/i18n/langFR";
+
+const Page: React.FC = () => {
+  const option = {
+    title: {
+      text: 'ECharts 入门示例'
+    },
+    toolbox: {
+        feature: {
+            saveAsImage: {},
+            dataZoom: {},
+            restore: {}
+        }
+    },
+    tooltip: {},
+    legend: {
+      data:['销量']
+    },
+    xAxis: {
+      data: ['衬衫', '羊毛衫', '雪纺衫', '裤子', '高跟鞋', '袜子']
+    },
+    yAxis: {},
+    series: [{
+      name: '销量',
+      type: 'line',
+      data: [5, 20, 36, 10, 10, 20]
+    }]
+  };
+
+  return <ReactECharts
+    option={option}
+    style={{ height: 400 }}
+    opts={{ locale: 'FR' }}
+  />;
+};
+
+export default Page;
+```

src/types.ts

@@ -9,6 +9,7 @@ export type Opts = {
   readonly renderer?: 'canvas' | 'svg';
   readonly width?: number | null | undefined | 'auto';
   readonly height?: number | null | undefined | 'auto';
+  readonly locale?: string;
 };
 
 export type EChartsReactProps = {