Add The Black Hole Register as a vim til.

README.md

@@ -66,6 +66,7 @@ smart people at [Hashrocket](http://hashrocket.com/).
 
 ### vim
 
+- [The Black Hole Register](vim/the-black-hole-register.md)
 - [Buffer Time Travel](vim/buffer-time-travel.md)
 - [Close the Current Buffer](vim/close-the-current-buffer.md)
 - [Count the Number of Matches](vim/count-the-number-of-matches.md)

vim/the-black-hole-register.md

@@ -0,0 +1,19 @@
+# The Black Hole Register
+
+Vim has a variety of registers for storing and moving around text. Vim also
+has a special register called the *black hole register*.
+
+> When writing to this register, nothing happens.  This can be used to delete
+> text without affecting the normal registers.  When reading from this register,
+> nothing is returned.
+
+As stated in the docs, if you don't want to overwrite the unnamed register or
+some other register when deleting text, you can use the black hole register.
+For instance, to deleting the current line without any register side-effects
+looks like this:
+
+```
+"_dd
+```
+
+See `:h registers` for more info on Vim's registers.