Fix documentation formatting

Author: natemcmaster

docs/docs/arguments.md

@@ -17,7 +17,7 @@ They have one defining characteristic.
 
 ### [Using Attributes](#tab/using-attributes)
 
-@McMaster.Extensions.CommandLineUtils.ARgumentAttribute can be used on properties to define arguments.
+@McMaster.Extensions.CommandLineUtils.ArgumentAttribute can be used on properties to define arguments.
 The argument order must be specified explicitly.
 
 ```c#
@@ -127,6 +127,8 @@ public class Program
 }
 ```
 
+***
+
 ## Pass-thru arguments
 
 Another common scenario is to create a command line tool which wraps another tool. These kinds of command lines