Multiply two inputs

### User story
As an analytical code developer, I want a function that multiples two numbers together, so that I can practice using Git.

### Definition of done
- [ ] Runs without error
- [ ] Fully meets the user requirements
- [ ] Documented using a [docstring for python](https://peps.python.org/pep-0257/) or [roxygen2 comment for R](https://cran.r-project.org/web/packages/roxygen2/vignettes/roxygen2.html)
- [ ] Peer reviewed and updated if needed

Start by inspecting the repository to identify the intended language, entry point, and existing tests. Add the requested function for multiplying two inputs, document it with the applicable Python docstring or R roxygen2 comment, and run the available checks to confirm it executes without error.

Written by the indexing model from the issue text.