docs(json): fix @example import path to real export

The @example in `getEditableJsonClass` imports from `@socketsecurity/lib/json`, which is not a package.json export — only `./json/edit`, `./json/format`, `./json/parse`, `./json/types` exist. Consumers copy-pasting this snippet would hit "Cannot find module" at runtime. Points at the correct subpath the test file already uses.

Author: jdalton

src/json/edit.ts

@@ -158,7 +158,7 @@ async function retryWrite(
  *
  * @example
  * ```ts
- * import { getEditableJsonClass } from '@socketsecurity/lib/json'
+ * import { getEditableJsonClass } from '@socketsecurity/lib/json/edit'
  *
  * const EditableJson = getEditableJsonClass<MyConfigType>()
  * const config = await EditableJson.load('./config.json')