[NEW TOOL] loan calculator

[cgoIT]

Describe the solution you'd like
A simple tool to calculate loans.

Is their example of this tool in the wild?
Example lib: https://github.com/timmson/loan-schedule.js
Demo: https://timmson.github.io/loan-schedule-ui/?amount=15+000.00&rate=6&term=240&paymentAmount=250.00&issueDate=07.05.2023&paymentOnDay=1

Additional context
From my point of view the provided lib as an example is good, but the demo has some limitations (e.g. try to set 0 as term and see what happens ;)).
If such a tool is not wanted (no it reference) it's also fine for me. If it is desired I could try to provide a PR.