OctOS: Add echo command

Prints text to the command line.

doc/computers/commands.md

@@ -2,9 +2,10 @@
 OctOS is the operating system used by digicomputers. OctOS is made of many Linux-like commands which are documented under the Commands section, however, there is also an API which can be used when writing programs for OctOS which is documented in `os_api.md`. Available commands are documented below.
 
 #### `help [command, "all"]`
-
 Shows help about the command specified or all commands if `all` is specified.
 
 #### `lua [code]`
+Runs Lua code from the command line under the secure environment.
 
-Runs Lua code from the command line under the secure environment.
+#### `echo [text]`
+Print text to the command line.

octos/bin/echo

@@ -0,0 +1,3 @@
+name = echo
+description = Print text to the command line
+exec = os/exec/echo.lua

octos/exec/echo.lua

@@ -0,0 +1,4 @@
+local params = ...
+local text   = (table.concat(params, " "))
+
+print(text)