Update story_emot.md

docs/cutscenes/story_emot.md

@@ -20,6 +20,7 @@ Create a character format: `[!CXY<Z>]`
 - X determines the conversation ID of the created character. (1-6?)
 - Y determines which character is created. (A-Z)
 - Z determines distance from opposite of facing side. (0-9)
+- `-` causes the text box to change color without showing a portrait or speaker name
 - Wrapping Z in `<>` causes the character to face left, `><` faces right
  
 Edit character emotions format: `[!EXYZ]`