show provider of exchange rates data and map in about page

src/lib/map/amap.js

@@ -11,6 +11,10 @@ const amapHolder = {
     AMap: null
 };
 
+export function getAmapWebsite() {
+    return 'https://www.amap.com';
+}
+
 export function loadAmapAssets() {
     if (amapHolder.AMap) {
         return;

src/lib/map/baidumap.js

@@ -10,6 +10,10 @@ const baiduMapHolder = {
     COORDINATES_BD09: window.COORDINATES_BD09 || 5
 };
 
+export function getBaiduMapWebsite() {
+    return 'https://map.baidu.com';
+}
+
 export function loadBaiduMapAssets() {
     if (baiduMapHolder.BMap) {
         return;

src/lib/map/googlemap.js

@@ -8,6 +8,10 @@ const googleMapHolder = {
     }
 };
 
+export function getGoogleMapWebsite() {
+    return 'https://maps.google.com';
+}
+
 export function loadGoogleMapAssets(language) {
     if (googleMapHolder.googleMap) {
         return;

src/lib/map/index.js

@@ -13,6 +13,7 @@ import {
 } from './leaflet.js';
 
 import {
+    getGoogleMapWebsite,
     loadGoogleMapAssets,
     createGoogleMapHolder,
     createGoogleMapInstance,
@@ -22,6 +23,7 @@ import {
 } from './googlemap.js';
 
 import {
+    getBaiduMapWebsite,
     loadBaiduMapAssets,
     createBaiduMapHolder,
     createBaiduMapInstance,
@@ -31,6 +33,7 @@ import {
 } from './baidumap.js';
 
 import {
+    getAmapWebsite,
     loadAmapAssets,
     createAmapHolder,
     createAmapInstance,
@@ -39,6 +42,20 @@ import {
     removeAmapCenterMaker
 } from './amap.js';
 
+export function getMapWebsite() {
+    if (getMapProvider() === 'custom') {
+        return '';
+    } else if (mapConstants.leafletTileSources[getMapProvider()]) {
+        return mapConstants.leafletTileSources[getMapProvider()].website;
+    } else if (getMapProvider() === 'googlemap') {
+        return getGoogleMapWebsite();
+    } else if (getMapProvider() === 'baidumap') {
+        return getBaiduMapWebsite();
+    } else if (getMapProvider() === 'amap') {
+        return getAmapWebsite();
+    }
+}
+
 export function loadMapAssets(language) {
     if (mapConstants.leafletTileSources[getMapProvider()] || getMapProvider() === 'custom') {
         return loadLeafletMapAssets(language);