Update Inference specification for Hugging Face's completion and chat completion tasks (#4383)

* Update Inference specification for Hugging Face's completion and chat completion tasks

* Extend description for url parameter

* Fix model_id description for text_embedding task and update endpoint creation comment

* Enhance Hugging Face integration documentation for chat completion and completion tasks

* Add @typescript-eslint/rule-tester to devDependencies in package-lock.json

* Enhance Hugging Face integration to support chat_completion and completion tasks

* Fix description for model_id field in Hugging Face integration to clarify request failure conditions

* Update json schema

Author: Jan-Kazlouski-elastic