Improve error handling

[StefMa]

Right now I just push the err I got from various calls back.
I might want to add additional information to it like API call failed with the following error: + err.

[StefMa]

Example:
When running ollama but using an model that is not pulled (available) I get returned an empty string.

$ go run cmd/summaraizer/summaraizer.go reddit --post r/ArtificialInteligence/comments/1d16cxl/miss_ai_worlds_first_beauty_contest_with_computer/ | go run cmd/summaraizer/summaraizer.go ollama

Output:

(Nothing 🤓 )