Add API documentation for TrackGo HTTP API and enhance employee management features

- Created a new `api.md` file detailing the TrackGo HTTP API, including authentication, user management, and employee operations.
- Updated `Employee` type to simplify user relation handling by replacing `UserRelation` with a more concise structure.
- Enhanced filtering capabilities in employee queries to support an array of positions.
- Refactored employee-related services and repositories to accommodate the new position filtering logic.
- Added unit and e2e tests to validate the new API documentation and employee management functionalities.

src/modules/configuration/employees/employees.repository.spec.ts

@@ -45,8 +45,6 @@ describe('EmployeesRepository', () => {
     userId: null,
   };
 
-  const joinedRow = { employee: row, user: null };
-
   const createInput = {
     code: 'EMP_01',
     name: 'Ada Lovelace',
@@ -144,7 +142,7 @@ describe('EmployeesRepository', () => {
       name: 'Ada',
       code: 'EMP',
       phone: '+628',
-      position: 'sales',
+      position: ['sales', 'driver'],
       status: 'draft',
       search: 'ada',
       limit: 10,