feat: Add an "official" indicator in the library

In the model library on ollama.com, there is no indication whether a model is "official", e.g., provided by the ollama team, or uploaded by a user, other than the username prefix. This can cause confusion for other users searching for a model by name. Recommend implementing something similar to Docker Hub to indicate models provided by Ollama team, models provided by Model developer and models supported / blessed by Ollama team.