[BUG / DATA] srd-2024 Champion Fighter subclasses features missing level assignments

[calumbell]

Bug description

Currently on the staging branch of the API, the ClassFeatureItem data for the srd-2024 Champion (Fighter subclass) is miss. This is essential information for using the subclass as it explains at what level specific subclass features are gained.

It also messes up my precious styling on the front end 😢:

The Path of the Berserker (srd-2024 Barbarian subclass) has level annotations next to the ability title:

But these are missing on the srd-2024 Champion subclass page (due to the missing data).

The fix is simple enough, add the missing data to the data/v2/wizards-of-the-coast/srd-2024/ClassFeatureItem.json file.

Steps to Reproduce

1. Visit the srd-2024 Champion subclass beta API endpoint on the beta site. Note that "gained_at" array is empty.

2. Compare this to the srd-2024 Berserker subclass beta API endpoint. The "gained_at" array is populated with data describing the level(s) a feature is gained.