Typo "revenue" is misspelled as "reeenue"

[lisvrijsen]

User noticed a typo on page https://docs.apify.com/academy/get-most-of-actors/monetizing-your-actor#pay-per-result-unit-pricing-for-cost-computation.

The word "revenue" is misspelled as "reeenue"

[TC-MO]

Closed with #1619