feat: integrate PersonalMilestoneModule into GraphQL module and update its configuration

- Added PersonalMilestoneModule to the GraphQL module imports, enhancing the overall functionality and data management.
- Updated PersonalMilestoneModule to use providers and exports for PersonalMilestoneSchema, improving module encapsulation and reusability.

src/PersonalMilestone/personalmilestone.module.ts

@@ -2,6 +2,7 @@ import { Module } from '@nestjs/common'
 import { PersonalMilestoneSchema } from './personalmilestone.schema'
 
 @Module({
-  imports: [PersonalMilestoneSchema],
+  providers: [PersonalMilestoneSchema],
+  exports: [PersonalMilestoneSchema],
 })
 export class PersonalMilestoneModule {}