Our check for whether to include launch buttons just checks whether any launch button config is present. However this means somebody can specify some config, but none that result in valid launch buttons, and this will result in an empty drop-down.
This is relevant because jupyter book sets some default config, and so launch_buttons will always be present.
We should improve the check so that launch buttons only show if a valid button link can be created.
Our check for whether to include launch buttons just checks whether any launch button config is present. However this means somebody can specify some config, but none that result in valid launch buttons, and this will result in an empty drop-down.
This is relevant because jupyter book sets some default config, and so launch_buttons will always be present.
We should improve the check so that launch buttons only show if a valid button link can be created.