* added secondary action
* create book command
* open as untitled
* create toc.yml and update title
* added comments
* throw error if filenames have unsupported chars
* update prompt message
* remove the toLocaleLower
* added await
* moced createbookpath out of the command handler
* removed tolocalelower and added comments
* moved the formatting and file handling code from core to notebook
* fixes for contents with folders
* collapse the code cell
* remove output
* reused existing command to open book
* comment typu and added await
