Fix typos & add documentation (#3569)

* fix typo

* tips & typos

* improve doc string

* update documentation

* fmt

* fix typo

src/chat.rs

@@ -2863,7 +2863,7 @@ pub async fn remove_contact_from_chat(
     let mut success = false;
 
     /* we do not check if "contact_id" exists but just delete all records with the id from chats_contacts */
-    /* this allows to delete pending references to deleted contacts.  Of course, this should _not_ happen. */
+    /* this allows to delete pending references to deleted contacts. Of course, this should _not_ happen. */
     if let Ok(chat) = Chat::load_from_db(context, chat_id).await {
         if chat.typ == Chattype::Group || chat.typ == Chattype::Broadcast {
             if !chat.is_self_in_chat(context).await? {

src/mimefactory.rs

@@ -445,6 +445,8 @@ impl<'a> MimeFactory<'a> {
             .collect()
     }
 
+    /// Consumes a `MimeFactory` and renders it into a message which is then stored in
+    /// `smtp`-table to be used by the SMTP loop
     pub async fn render(mut self, context: &Context) -> Result<RenderedEmail> {
         let mut headers: MessageHeaders = Default::default();
 

src/param.rs

@@ -163,7 +163,7 @@ pub enum Param {
     /// For Chats: timestamp of group name update.
     GroupNameTimestamp = b'g',
 
-    /// For Chats: timestamp of group name update.
+    /// For Chats: timestamp of member list update.
     MemberListTimestamp = b'k',
 
     /// For Chats: timestamp of protection settings update.