allow multiple provide

package.json

 {
   "name": "koishi-nestjs",
-  "version": "1.2.0",
+  "version": "1.2.1",
   "description": "Koishi.js as Nest.js Module",
   "main": "dist/index.js",
   "typings": "dist/index.d.ts",

src/koishi.decorators.ts

@@ -174,5 +174,5 @@ export function WireContextService(name?: string): PropertyDecorator {
 
 export function ProvideContextService(name: string): ClassDecorator {
   Context.service(name as keyof Context.Services);
-  return SetMetadata(KoishiServiceProvideSym, name);
+  return SetExtraMetadata(KoishiServiceProvideSym, name);
 }

src/providers/koishi-metascan.service.ts

@@ -158,12 +158,14 @@ export class KoishiMetascanService {
   }
 
   private scanInstanceForProvidingContextService(ctx: Context, instance: any) {
-    const providingServiceName = this.reflector.get(
+    const providingServiceNames: string[] = this.reflector.get(
       KoishiServiceProvideSym,
       instance.constructor,
     );
-    if (providingServiceName) {
-      ctx[providingServiceName] = instance;
+    if (providingServiceNames) {
+      for (const name of providingServiceNames) {
+        ctx[name] = instance;
+      }
     }
   }