docs: Command-completion additional refs section

docs/command-completion.md

@@ -4,15 +4,15 @@ Command Completion
 Shell command completion is provided by the script at 
 `/misc/completion/ipfs-completion.bash`.
 
+
+Installation
+------------
 The simplest way to see it working is to run 
 `source misc/completion/ipfs-completion.bash` straight from your shell. This
 is only temporary and to fully enable it, you'll have to follow one of the steps
 below.
 
-Linux
------
-### Bash
-
+### Bash on Linux
 For bash, completion can be enabled in a couple of ways. One is to add
 ```bash
 if [ -n "$GOPATH" ]; then
@@ -23,3 +23,8 @@ into your `~/.bash_completion`. It will automatically be loaded the next time
 bash is loaded.
 To enable ipfs command completion globally on your system you may also 
 copy the completion script to `/etc/bash_completion.d/`.
+
+
+Additional References
+---------------------
+* https://www.debian-administration.org/article/316/An_introduction_to_bash_completion_part_1