Added pacman in install options.

Arch needs to be appreciated :)

README.md

@@ -33,7 +33,7 @@ Scope:
 
 Notes:
 
-- To keep this to one page, content is implicitly included by reference. You're smart enough to look up more detail elsewhere once you know the idea or command to Google. Use `apt-get`/`yum`/`dnf`/`pip`/`brew` (as appropriate) to install new programs.
+- To keep this to one page, content is implicitly included by reference. You're smart enough to look up more detail elsewhere once you know the idea or command to Google. Use `apt-get`/`yum`/`dnf`/`pacman`/`pip`/`brew` (as appropriate) to install new programs.
 - Use [Explainshell](http://explainshell.com/) to get a helpful breakdown of what commands, options, pipes etc. do.
 
 
@@ -59,7 +59,7 @@ Notes:
 
 - Know regular expressions well, and the various flags to `grep`/`egrep`. The `-i`, `-o`, `-A`, and `-B` options are worth knowing.
 
-- Learn to use `apt-get`, `yum`, or `dnf` (depending on distro) to find and install packages. And make sure you have `pip` to install Python-based command-line tools (a few below are easiest to install via `pip`).
+- Learn to use `apt-get`, `yum`, `dnf` or `pacman` (depending on distro) to find and install packages. And make sure you have `pip` to install Python-based command-line tools (a few below are easiest to install via `pip`).
 
 
 ## Everyday use