feat: getNitroStickerPacks() -> getStickerPacks() (#109)

* feat: getNitroStickerPacks() -> getStickerPacks()

Sticker packs that used to be Nitro-only are free now - this slipped under the radar.

Ref: discord/discord-api-docs#6265

* fix typos

* reword the deprecation message along with reasoning

index.d.ts

@@ -2919,6 +2919,7 @@ declare namespace Dysnomia {
     getRoleConnectionMetadata(): Promise<ApplicationRoleConnectionMetadata[]>;
     getSelf(): Promise<ExtendedUser>;
     getStageInstance(channelID: string): Promise<StageInstance>;
+    getStickerPacks(): Promise<{ sticker_packs: StickerPack[] }>;
     getThreadMember(channelID: string, memberID: string, options: GetThreadMemberOptions): Promise<ThreadMember>;
     getThreadMembers(channelID: string, options: GetThreadMembersOptions): Promise<ThreadMember[]>;
     getVoiceRegions(guildID?: string): Promise<VoiceRegion[]>;

lib/Client.js

@@ -2687,10 +2687,10 @@ class Client extends EventEmitter {
 
     /**
      * Get the list of sticker packs available to Nitro subscribers
-     * @returns {Promise<Object>} An object whichs contains a value which contains an array of sticker packs
+     * @returns {Promise<Object>} An object which contains a value which contains an array of sticker packs
      */
     getNitroStickerPacks() {
-        return this.requestHandler.request("GET", Endpoints.STICKER_PACKS, true);
+        return this.getStickerPacks();
     }
 
     /**
@@ -2944,6 +2944,14 @@ class Client extends EventEmitter {
         return this.requestHandler.request("GET", Endpoints.STAGE_INSTANCE(channelID), true).then((instance) => new StageInstance(instance, this));
     }
 
+    /**
+     * Get the list of available sticker packs
+     * @returns {Promise<Object>} An object which contains a value which contains an array of sticker packs
+     */
+    getStickerPacks() {
+        return this.requestHandler.request("GET", Endpoints.STICKER_PACKS, true);
+    }
+
     /**
      * Gets a thread member object for a specified user
      * @arg {String} channelID The ID of the thread channel