Do not include compiled params.yaml in git repo

[grst]

Pro

The file is automatically generated. Automatically generated filese are typically not included in a git repo
It adds noise to code-review and diffs

Con

the compiled configuration is frozen and reproducible in each commit (dso tooling might change over time and config files might compile different in the future - not expecting anything here, but what if a bug is found in the library that resolves the configs)
you can run the project without the dso helper using plain dvc. 

We initially decided to keep params.yaml checked into git, but there are also good reasons not to. Let's try it out in one of the projects and see if it has any other unintended side effects. 

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Another issue with this setup is that

dvc pull

after an initial clone will fail unless

dso compile-config

is run first.

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dso compile-config hook should run on post-checkout before dso checkout in that case

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If we do that, I'd like to freeze the dso version for each project. Here's an idea how to do that: github.com//issues/6