add a comment about commandSplitter()'s usage

Author: notnmeyer

projects/optic/src/utils/capture.ts

@@ -6,6 +6,10 @@ export type SpawnCommand = {
   args: string[];
 };
 
+// commandSplitter() splits a command and its args into a SpawnCommand--in a naive fashion. it
+// assumes that `command` contains a single command, rather than something more complex. since
+// there is no validation or safety checks performed on `command` exercise caution where you
+// use this.
 export function commandSplitter(command: string): SpawnCommand {
   return {
     cmd: command.split(' ')[0],