mbed - Add library, program and create new cookbook (tip & tricks)

I have added new libraries to mbed. That was quite intuitive. I faced one problem, if you upload your own files, there are only two options - add program or library. Firstly, I added files as library, create a folder and moved all files there. I also added files as program and then moved them. What I consider as missing part there, add Folder to a project with desired name.
Adding files has its limits (I was able to import only 20 files, more were ignored).

I realized that I was adding libraries (different symbol than normal folder) at the moment when I was about to commit new library ( it asked to commit all libraries which are part of the library).
There is folder (folder icon) and mbed-rtos which is the library icon.

Another one, how to add new page to the cookbook. Here's an explanation, google was not my friend in the beginning:

mbed cookbook [http://mbed.org/cookbook]

Create new link (an example http://mbed.org/cookbook/my_new_link), start editing.