Clarify indexes in CharData and IColorRGB

Part of #5740

Author: Tyriar

src/common/Types.ts

@@ -101,13 +101,13 @@ export interface ICharset {
   [key: string]: string | undefined;
 }
 
-export type CharData = [number, string, number, number];
+export type CharData = [attrIndex: number, charIndex: string, width: number, code: number];
 
 export interface IColor {
   readonly css: string;
   readonly rgba: number; // 32-bit int with rgba in each byte
 }
-export type IColorRGB = [number, number, number];
+export type IColorRGB = [red: number, green: number, blue: number];
 
 export interface IExtendedAttrs {
   ext: number;