Prompt Title: Filter JSON for non-null languages.

In the context of the del(.. | .es?, .ja?, .pt_br?, .zh_chs?) expression, the .. represents the recursive descent operator in jq.

The .. operator allows you to match any key at any level of the JSON hierarchy. It is often used in combination with other operators or functions to perform operations on all matching elements in the JSON structure.

In the given script, .. | .es?, .ja?, .pt_br?, .zh_chs? uses the recursive descent operator .. to match any key at any level of the JSON hierarchy. The subsequent | (pipe) operator is used to apply the filter expression .es?, .ja?, .pt_br?, .zh_chs? to each matching element.

The ? operator after each language field (e.g., .es?) is the optional field operator in jq. It selects the value of the field if it exists, and if the field does not exist, it produces no output. Therefore, when applied to each matching element, it effectively removes the specified language fields (es, ja, pt_br, zh_chs) from the JSON structure.

So, del(.. | .es?, .ja?, .pt_br?, .zh_chs?) will remove the specified language fields from the entire JSON hierarchy, including nested objects, by matching any key at any level and deleting the fields if they exist.