feat: complete auth and submission's swagger docs

src/modules/submissions/dtos/answer-submission.dto.ts

@@ -1,18 +1,22 @@
 import { IsArray, IsInt, IsNumber, IsOptional } from 'class-validator';
 import { SubmissionAnswer } from '../decorators/submission-answer.decorator';
+import { ApiPropertyOptional } from '@nestjs/swagger';
 
 export class AnswerSubmissionDTO {
   @IsNumber()
   @IsOptional()
+  @ApiPropertyOptional()
   choiceId?: number;
 
   @IsArray()
   @IsOptional()
   @IsInt({ each: true })
+  @ApiPropertyOptional({ isArray: true, type: 'number' })
   choiceIds?: number[];
 
   @IsNumber()
   @IsOptional()
+  @ApiPropertyOptional()
   numericValue?: number;
 
   @SubmissionAnswer()