What is there in Coin Change.md?
Only a variation of unbounded Knapsack

Issue:
There exists many more variations like having a fixed number of coins or say a problem where we want to find the number of ways (ordered) a sum of money can be formed

Suggested Solution:
We can add these two explanations separately in files.

Description

Recently I closed out issue #321 with PR #328 to add a database to track lookups. I mistakenly didn't really add any unit tests along with this to verify functionality and ensure things stay reliable during PRs and CI/CD. This issue should add some in.

Requirements

1. Test the new Models that were added
2. Ensure page visits store in the database

Is your feature request related to a problem? Please describe.
Would like to auto greet new people

Describe the solution you'd like
https://github.com/marketplace/actions/first-interaction

Describe alternatives you've considered
Manual is slower and error prone and also not very fancy

Additional context
Let's come up with something interesting to say on `First interac

The test suite is currently somewhat weak with respect to testing error cases and validating the resulting error messages.

The test suite should probably move tests that check error cases into a separate directory.