Add link to documentation in Custom LLM description

[nicola-corbellini]

Description

I added a link key to the LLMCustomConfig schema so @zAlweNy26 can point the user to the tutorial on the website.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas

[nicola-corbellini]

to keep schemas consistent what about adding a link to the vendor's pages for the others LLM options? Otherwise I can close this PR, it is not crucial having a link to the website

[pieroit]

to keep schemas consistent what about adding a link to the vendor's pages for the others LLM options? Otherwise I can close this PR, it is not crucial having a link to the website

Yes it has to be consistent to avoid spaghetti solutions, but this seems a good one to me.

[nicola-corbellini]

@zAlweNy26 is not happy of this 😂
@pieroit ok I'll open a new pr with the other links then