Bump tdlib/td@789b9c0 and Closes #7 fewensa/telegram-client#31 and update README/version

Author: fewensa

README.md

@@ -13,30 +13,19 @@ rtdlib
 
 ```toml
 [dependencies]
-rtdlib = "0.8.*"
+rtdlib = "1.8.*"
 ```
 
 The default, `rtdlib` only have `td` types, not have call tdjson dylib, if you want , you need add `features` to your dependency.
 
 ```toml
 [dependencies]
-rtdlib = { version = "0.8.*", features = "sys" }
+rtdlib = { version = "1.8.*", features = "sys" }
 ```
 
 ## version
 
-Version mapping
-
-| rtdlib        | td          |
-|---------------|-------------|
-| 0.*           | [master@fa8feef](https://github.com/tdlib/td/commit/fa8feefed70d64271945e9d5fd010b957d93c8cd) |
-| 1.8.*         | 1.8.*       |
-
-The version `1.3`, `1.4`, `1.5`, `1.6`, `1.7` is outdated. the reason you can read
-
-- [A new telegram client update](https://github.com/fewensa/telegram-client/issues/29)
-- [UPDATE_APP_TO_LOGIN](https://github.com/tdlib/td/issues/1758)
-
+Please read: [version](https://github.com/fewensa/telegram-client/blob/master/version.md)
 
 # Example
 

src/types/background.rs

@@ -16,7 +16,7 @@ pub struct Background {
   #[serde(rename(serialize = "@extra", deserialize = "@extra"))]
   extra: Option<String>,
   /// Unique background identifier
-  id: isize,
+  #[serde(deserialize_with = "serde_aux::field_attributes::deserialize_number_from_string")] id: isize,
   /// True, if this is one of default backgrounds
   is_default: bool,
   /// True, if the background is dark and is recommended to be used with dark theme

src/types/check_chat_username_result.rs

@@ -23,7 +23,7 @@ pub enum CheckChatUsernameResult {
   CheckChatUsername(CheckChatUsername),
   /// The username can be set
   Ok(CheckChatUsernameResultOk),
-  /// The user has too much chats with username, one of them must be made private first
+  /// The user has too many chats with username, one of them must be made private first
   PublicChatsTooMuch(CheckChatUsernameResultPublicChatsTooMuch),
   /// The user can't be a member of a public supergroup
   PublicGroupsUnavailable(CheckChatUsernameResultPublicGroupsUnavailable),
@@ -191,7 +191,7 @@ impl AsRef<CheckChatUsernameResultOk> for RTDCheckChatUsernameResultOkBuilder {
 
 
 
-/// The user has too much chats with username, one of them must be made private first
+/// The user has too many chats with username, one of them must be made private first
 #[derive(Debug, Clone, Default, Serialize, Deserialize)]
 pub struct CheckChatUsernameResultPublicChatsTooMuch {
   #[doc(hidden)]