docs: Clarify compiler.cmd_array()
Make it easier to understand that this array contains the compiler
command, not arguments to it, and may only have one element.
@@ -2236,8 +2236,7 @@ the following methods:
the positional argument, you can specify external dependencies to
use with `dependencies` keyword argument.
-- `cmd_array()`: returns an array containing the command arguments for
- the current compiler.
+- `cmd_array()`: returns an array containing the command(s) for the compiler.
- `compiles(code)`: returns true if the code fragment given in the
positional argument compiles, you can specify external dependencies
