Update IMPLEMENTATIONS.md
Update IMPLEMENTATIONS.md

springdoc-openapi is a java library that produces OpenAPI 3.x specification documentation for spring-boot applications. 
It helps automating the generation of API documentation using spring boot projects.
It automatically deploys swagger-ui to a spring-boot application Documentation.

Automatically generates documentation in JSON/YAML and HTML format APIs. This documentation can be completed by comments using swagger-api annotations.

This library supports:

OpenAPI 3
Spring-boot 2
JSR-303, specifically for @NotNull, @Min, @Max, and @Size.
Swagger-ui
Oauth 2
OAI/OpenAPI-Specification,OAI/OpenAPI-Specification,OAI/OpenAPI-Specification