Top-level bullets for AI in the docs

[m0mus]

Resolves #10550

Adds MCP Server docs

[hyder]

Under General Concepts > Creating Components

1. Change "Supported LangChain4j components are automatically created and registered in service registry if exists the corresponding configuration and enabled property is set to true." to
   "Supported LangChain4j components are automatically created and registered in service registry if the corresponding configuration exists and enabled property is set to true."

2. Change "For example, adding the following lines to application.yaml cause of automatic creating and registering OpenAiChatModel, which later can be injected in other classes of your application:" to

"For example, adding the following lines to application.yaml causes the automatic creation and registration OpenAiChatModel, which later can be injected in other classes of your application:"

Under Supplier Factory

"This method is not limited to LangChain4j and suitable for creating and registering other classes." This should be documented somewhere else.

"By default, the default or unnamed Helidon bean is created. To create a named service, you need to add @Service.Named("name") annotation."

How does a user use the newly named service? It would be good to provide a link to an example here.

Under Injecting Components:

"You can inject Helidon services into another Helidon services using constructor injection like this:"

Typo. Please change: "You can inject a Helidon service into another Helidon service using constructor injection like this:"

The generic example should be in the same location as for supplier factory. Here, keep a concrete example for LangChain4j.

Under Creating AI Service:
"It’s a pure LangChain4j component.". What does being pure mean? are there other types of components?

MCP Client should go to the MCP page.

[m0mus]

The purpose of this PR is moving AI docs to the root location and add MCP page. Changing LC4j docs is out scope. Please create another issue for it and assign it to me.

[hyder]

comments inline

[hyder]

Approved. I'll create an issue for the other one.