Add a til on the Head of File Name modifier.

vim/head-of-file-name.md

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+# Head of File Name
+
+At Hashrocket, I kept seeing my coworkers type a variety of commands into
+vim command mode that included `%:h`. I finally decided to ask what was
+going on. It turns out that it produces the directory of the file in your
+current vim buffer.
+
+The `%` represents the current file and `:h` is a filename modifier,
+*head of the filename*, that truncates the last component and any
+separators. So if you remove the file part of the current file (`%`), you
+are left with the (relative) directory of the current file. Your imagination
+and vim's flexibility can now take over.
+
+A common use case is to use it to quickly edit another file that you know is
+in the same directory. Why type out a long pathname over and over throughout
+the day, when you can type:
+
+```
+:e %:h<tab>
+```
+
+After hitting tab, the pathname will be auto-completed. Complete the rest of the
+filename as you do.
+
+Or perhaps you aren't sure what file you want to edit and you'd rather just
+get a picture of the whole directory:
+
+```
+:e %:h
+```
+
+You are now exploring the whole directory in netrw mode. Yay!
+
+If you want to find out more about similar features,
+there is a section in the Vim documentation that talks all about [filename
+modifiers](http://vimdoc.sourceforge.net/htmldoc/cmdline.html#filename-modifiers).