Documentation issue: docker pull ollama/gemma2:2b -> repository does not exist

The README.md file says to pulled the `gemma2:2b` model by running "docker pull ollama/gemma2:2b", but this image does not exist. I believe the command should be "ollama pull ...", not "docker pull". Also gemma2:2b is no longer supported, so something like "ollama pull gemma3:1b" would now work.