Missing dependency `spring-boot-starter-validation`

[Paweł Podkalicki]

The org.springframework.boot:spring-boot-starter-validation dependency is not mentioned in the instruction. It is not present in the initial code, but it is in the complete code. Following the instruction step-by-step will not produce the desired result.

• Spring Initializr. Add Validation to dependencies.
  In the current version is:

This example needs the Spring Web and Thymeleaf dependencies.

Should be:

This example needs the Spring Web, Thymeleaf and Validation dependencies.

• Maven. Add validation library to dependencies:

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-validation</artifactId>
		</dependency>

• Gradle. Add validation library to dependencies:

	implementation 'org.springframework.boot:spring-boot-starter-validation'

• The initial code should have this dependency as well.