[FEATURE] Update difficulty level `3` (out of `5`) from `Neutral` to `Medium`

[awpala]

Is your feature request related to a problem? Please describe.

"Neutral" seems like an incongruent descriptor with respect to "difficulty"; "medium" seems more appropriate.

Describe the solution you'd like

Change the label from "neutral" to "medium."

Describe alternatives you've considered

(N/A)

Additional context

(N/A)