Need instructions for adding new scripts in the src/ folder and adding packages to the renv lockfile.

[zkamvar]

I was unable to run #289 from the src/ folder because it contains the scoringRules package, which is not in src/renv.lock and I realized the reason for this is that we do not have clear guidelines for the following:

1. adding a new R script to the src/ folder
2. adding a new package to src/renv.lock
3. updating packages in src/renv.lock (when necessary)