Refactor: Prune inst/extdata

[maurolepore]

Some files and folders don't seem to belong here

✗ tree inst
inst
└── extdata
    ├── mvp
    │   ├── 04_output_data_prep.Rmd
    │   └── 05_output_data_subsets.Rmd
    └── tiltIndicatorAfter_runner.Rmd