improve harmony integrated guide doc (#9)

* improve harmony guide doc

* update

* update

* improve harmony integrated guide doc

Author: bozaigao

site/pages/docs/getting-started.mdx

@@ -278,6 +278,54 @@ target_link_libraries(rnoh_app PUBLIC rnoh_pushy)
   }
 ```
 
+在 `harmony/entry/hvigorfile.ts` 中增加如下配置：
+```ts
+import { hapTasks } from '@ohos/hvigor-ohos-plugin';
+import fs from 'fs';
+import path from 'path';
+
+export function generatePushyBuildTime(str?: string) {
+    return {
+        pluginId: 'PushyBuildTimePlugin',
+        apply(pluginContext) {
+            pluginContext.registerTask({
+                name: 'pushy_build_time',
+                run: (taskContext) => {
+                    const metaFilePath = path.resolve(__dirname, 'src/main/resources/rawfile/meta.json');
+                    const dirPath = path.dirname(metaFilePath);
+                    if (!fs.existsSync(dirPath)) {
+                        fs.mkdirSync(dirPath, { recursive: true });
+                    }
+                    const moduleJsonPath = path.resolve(__dirname, '../AppScope/app.json5');
+                    let versionName = '';
+                    if (fs.existsSync(moduleJsonPath)) {
+                        const moduleContent = fs.readFileSync(moduleJsonPath, 'utf-8');
+                        const versionMatch = moduleContent.match(/"versionName":\s*"([^"]+)"/);
+                        if (versionMatch && versionMatch[1]) {
+                            versionName = versionMatch[1];
+                        }
+                    }
+                    const buildTime = new Date().toISOString();
+                    const metaContent = { 
+                        pushy_build_time: buildTime,
+                        versionName: versionName 
+                    };
+                    fs.writeFileSync(metaFilePath, JSON.stringify(metaContent, null, 4));
+                    console.log(`Build time written to ${metaFilePath}`);
+                },
+                dependencies: [],
+                postDependencies: ['default@BuildJS']
+            })
+        }
+    }
+}
+
+export default {
+    system: hapTasks,  /* Built-in plugin of Hvigor. It cannot be modified. */
+    plugins:[generatePushyBuildTime()]         /* Custom plugin to extend the functionality of Hvigor. */
+}
+```
+
 在 `harmony/entry/src/main/ets/RNPackagesFactory.ts` 代码如下：
 ```ts
 import type {RNPackageContext, RNPackage} from '@rnoh/react-native-openharmony/ts';