This commit changes the term "folder" to "directory" in every
instance where the first is used in an example description, but the
second is used in the example code, and vice versa.
These 6 files had multiple examples all separated by a single newline.
While rendering it in markdown, the examples all come up in a single
line.
Adding another newline makes rendering better.
Also will help in easier copying (double click on the line to copy).
Fixes#310
Some files had no newlines, some had 1 newline and some more than 1 newline.
Normalize them all to have only 1 newline at the end of all files.