Update Lookup in groups documentation about landing_page

[davidmyriel]

Will reach out asap with a draft.

[davidmyriel]

@joein I don't have access to chat, but I still owe you the help I promised. Can you paste the raw information here and I will add it to the documentation?

[joein]

In recommend and recommend groups we have an argument lookup_from

It has a brief description in the api reference
https://qdrant.github.io/qdrant/redoc/index.html#tag/points/operation/recommend_points:~:text=lookup_from-,LookupLocation%20(object)%20or%20(any%20or%20null),collection%20should%20have%20the%20same%20vector%20size%20as%20the%20current%20collection,-Responses

it is not mentioned in Recommendation API nor it is mentioned in Recommend groups

I thought about a scheme demonstrating that we fetch vectors from another collection by a point id but maybe we even don't need it and a simple description is enough