[Logging] YAML Indentation 3 Space in Docs

[michaelzhiluo]

Every YAML in our docs, https://sky-proj-sky.readthedocs-hosted.com/, has 3 spaces for indentation; As opposed to README.md, the indentation is 2 spaces.

Initial users will copy paste the YAML and modify it. 3 spaces make it difficult to modify YAML, as it conflicts with the spaces in the Tab key.