feat(commands): more types for detailed description (#372)

This backports 5f3fea4

src/lib/structures/Command.ts

@@ -1,5 +1,5 @@
 import { AliasPiece, AliasPieceJSON, PieceContext } from '@sapphire/pieces';
-import { Awaitable, isNullish } from '@sapphire/utilities';
+import { Awaitable, isNullish, NonNullObject } from '@sapphire/utilities';
 import { Message, PermissionResolvable, Permissions, Snowflake } from 'discord.js';
 import * as Lexure from 'lexure';
 import { Args } from '../parsers/Args';
@@ -24,7 +24,7 @@ export abstract class Command<T = Args, O extends Command.Options = Command.Opti
 	 * Longer version of command's summary and how to use it
 	 * @since 1.0.0
 	 */
-	public detailedDescription: string;
+	public detailedDescription: DetailedDescriptionCommand;
 
 	/**
 	 * The full category for the command. Either an array of strings that denote every (sub)folder the command is in,
@@ -408,7 +408,7 @@ export interface CommandOptions extends AliasPiece.Options, FlagStrategyOptions
 	 * @since 1.0.0
 	 * @default ''
 	 */
-	detailedDescription?: string;
+	detailedDescription?: DetailedDescriptionCommand;
 
 	/**
 	 * The full category path for the command
@@ -530,7 +530,7 @@ export interface CommandContext extends Record<PropertyKey, unknown> {
 
 export interface CommandJSON extends AliasPieceJSON {
 	description: string;
-	detailedDescription: string;
+	detailedDescription: DetailedDescriptionCommand;
 	category: string | null;
 }
 
@@ -541,3 +541,7 @@ export namespace Command {
 	export type RunContext = CommandContext;
 	export type RunInTypes = CommandOptionsRunType;
 }
+
+export type DetailedDescriptionCommand = string | DetailedDescriptionCommandObject;
+
+export interface DetailedDescriptionCommandObject extends NonNullObject {}