Tweego assumes that unless you indicate otherwise the source folder name(s) you pass to it are relative to the current folder/directory in which you calling the executable in.
eg. if the current folder/directory of your command shell is...
... then the following command line will find the src folder.
tweego -o project.html src
1. If you haven't opened your command shell in the folder you want to use as the 'root' folder of your project then you can use the CD command to make that folder the current one.
2. If you want to reference source folders that aren't relative to the current folder then you will need to use a more detailed filepath when indicating the source folder.
eg. By default the Windows Command Prompt opens with the current user's 'home' folder as the current folder/directory, so to reference the above 'src' folder from there you would need to use a command line something like the following. (the following assumes that the current user is PC)
tweego -o project.html Desktop\tweego\src