Remove individual browser names from browser schema; enforce one browser per JSON file (#15989)
Remove individual browser names from browser schema; enforce one browser per JSON file (#15989)

* Remove individual browser names from schema

* Revert changes that remove VS Code functionality

* Enforce one browser per file

* Add custom error messages
mdn/browser-compat-data,mdn/browser-compat-data,chrisdavidmills/browser-compat-data,chrisdavidmills/browser-compat-data