Fix documentations that were incorrect or missing (#1837)

* Fix docs for Guild#pruneMembers

* ClientApplication returns

* Guild#deleteEmoji

* Guild#setRolePosition takes RoleResolvable

* Client#fetchApplication returns ClientApplication not Oauth2Application

* ClientDataResolver#resolveImage can return null

* ClientApplication#toString small example

* Guild#allowDMs now has a only for user accounts warning

* ClientUserSettings#patch is private and setGuildPosition has a user account warning

* Role#setPermissions can take PermissionResolvable, not just String

* ChannelCreationOverwrites is for a role or a member, not for a "group"

* Fix ChannelData#userlimit string being wrong
"The user limit of voice the channel" :lul:

* ChannelResolvable is only for Channel or Snowflake

* EmojiIdentifierResolvable supports Snowflakes

* UserResolvable doesn't take a guild

* Make patch functions private

* Remove examples

* Webhoox#edit options.name defaults to the webhook name

* Make VoiceConnection functions private

* Am dum
The whole ClientUserSettings category is only for self bots soo

* Value for update functions is *

* Make update functions be private

* Fix GuildEditData missing Ssytemchannel property

* PermissionOverwriteOptions can accept null as an option
(Why did no-one document this?)

src/client/voice/VoiceConnection.js

@@ -150,6 +150,7 @@ class VoiceConnection extends EventEmitter {
   /**
    * Sends a request to the main gateway to join a voice channel.
    * @param {Object} [options] The options to provide
+   * @private
    */
   sendVoiceStateUpdate(options = {}) {
     options = Util.mergeDefault({
@@ -169,6 +170,7 @@ class VoiceConnection extends EventEmitter {
    * Set the token and endpoint required to connect to the voice servers.
    * @param {string} token The voice token
    * @param {string} endpoint The voice endpoint
+   * @private
    * @returns {void}
    */
   setTokenAndEndpoint(token, endpoint) {
@@ -201,6 +203,7 @@ class VoiceConnection extends EventEmitter {
   /**
    * Sets the Session ID for the connection.
    * @param {string} sessionID The voice session ID
+   * @private
    */
   setSessionID(sessionID) {
     if (!sessionID) {