ML LLM guide additions

[mvsjober]

Proposed changes

Add LUMI examples, SFTTrainer mentioned, Ollama example and discussion on quantization.

Preview: https://csc-guide-preview.2.rahtiapp.fi/origin/ml-llm-additions/support/tutorials/ml-llm/

Checklist before requesting a review

• I have followed the instructions in the Contributing and Styleguide documents.
• My pull request passes the automated tests. If not, visit pull requests at Travis CI and have a look at the job log.
• I have included a link to the appropriate preview page (select your branch from the list).

[mvsjober]

Note to self: Maybe add link to some overview of quantization in LLMs?

[mvsjober]

Possibly add link to: https://huggingface.co/blog/mlabonne/sft-llama3

[shanshanwangcsc]

all look good!