improve comments

Author: Anton-4

examples/command.roc

@@ -61,7 +61,7 @@ print_output! = |cmd_output|
             Stderr.line!(err_data)
 
         Err(err) ->
-            Stderr.line!("Failed to start executing command: ${Inspect.to_str(err)}")
+            Stderr.line!("Failed to get exit code for command, error: ${Inspect.to_str(err)}")
 
 
 # Run command with an environment variable

platform/Cmd.roc

@@ -130,15 +130,15 @@ output! = |@Cmd(cmd)|
     Host.command_output!(cmd)
     |> InternalCmd.from_host_output
 
-## Execute command and inherit stdin, stdout and stderr from parent
+## Execute command and inherit stdin, stdout and stderr from parent. Returns the exit code.
 ##
 status! : Cmd => Result I32 [CmdStatusErr InternalIOErr.IOErr]
 status! = |@Cmd(cmd)|
     Host.command_status!(cmd)
     |> Result.map_err(InternalIOErr.handle_err)
     |> Result.map_err(CmdStatusErr)
 
-## Execute command and inherit stdin, stdout and stderr from parent
+## Simplest way to execute a command while inheriting stdin, stdout and stderr from parent.
 ##
 ## ```
 ## # Call echo to print "hello world"