Here FROM x, function(x.column) is a shortened form of a lateral join which effectively joins every row from categories with virtual table created by jsonb_to_recordset function from jsonb array in that same row.
Editing JSON with Visual Studio Code. JSON is a data format that is common in configuration files like package.json or project.json. We also use it extensively in Visual Studio Code for our configuration files. When opening a file that ends with .json, VS Code provides features to make it simpler to write or modify the file's content.