Now, it's all under the notebook umbrella. Seems to be appropriate as it
is just my notes after all.
I also updated some notes from there. I didn't keep track of what it is
this time. Something about more learning notes extracted from my
"Learning how to learn" course notes and then some. Lack of time and
hurriness just makes it difficult to track but it should be under
version control already.
Hoorah! Finally made it through the course! On the other hand, I also
updated the `concat-asset-folder` function to accept multiple arguments
representing the directory hierarchy instead of a separator.
