unlike initializing a clean workspace, changing into an existing workspace sets dendron.rootDir to be the same folder as your vault
root.md, dendron.yml and dendron.code-workspace are added to your folder
none of your existing notes are modified during this process (unless they have the same name as the three files just named above)
no docs folder is created (if you want to publish, you can run Doctor to create the folder - note that this will also add frontmatter to all your existing notes)