Documentation improvements (#2069)

* docs: fix documentation in various places

All stores: resolveID returns a nullable Snowflake
GuildAuditLogs: ActionType also can be ALL
MessageEmbed: make files property show up in the docs
ClientApplication: resetSecret and resetToken return a promise
ClientManager: status is readonly
Guild: features is an array of strings and ban no longer accepts a number or string
Guild: ban method no longer accepts a string or number
GuildMember: ^
RichPresenceAssets: small and large Image are Snowflakes, also fixed parameter documentation for small and large image url method
WebhookMessageOptions: file property is no longer a thing

* docs: improve GuildAuditLogs documentation

Prefix types with AuditLog to avoid confusion
Document GuildAuditLogs' static Targets and Actions properties and add necessary typedefs
Use typdefs over primitives where possible.

* fix documentation for Guild#defaultRole

src/structures/ClientApplication.js

@@ -177,7 +177,7 @@ class ClientApplication extends Base {
   /**
    * Resets the app's secret.
    * <warn>This is only available when using a user account.</warn>
-   * @returns {ClientApplication}
+   * @returns {Promise<ClientApplication>}
    */
   resetSecret() {
     return this.client.api.oauth2.applications[this.id].reset.post()
@@ -187,7 +187,7 @@ class ClientApplication extends Base {
   /**
    * Resets the app's bot token.
    * <warn>This is only available when using a user account.</warn>
-   * @returns {ClientApplication}
+   * @returns {Promise<ClientApplication>}
    */
   resetToken() {
     return this.client.api.oauth2.applications[this.id].bot.reset.post()