- .say replacement fix

- .send and .qid now use smarttext instead of crembed
- added + operator for adding string to smarttext

src/NadekoBot/Common/SmartText/SmartText.cs

@@ -1,14 +1,28 @@
-using Newtonsoft.Json;
+using System;
+using Newtonsoft.Json;
 
 namespace NadekoBot
 {
-    public abstract class SmartText
+    public abstract record SmartText
     {
         public bool IsEmbed => this is SmartEmbedText;
         public bool IsPlainText => this is SmartPlainText;
 
-        public static implicit operator SmartText(string input)
-            => new SmartPlainText(input);
+        public static SmartText operator +(SmartText text, string input)
+            => text switch
+            {
+                SmartEmbedText set => set with { PlainText = set.PlainText + input },
+                SmartPlainText spt => new SmartPlainText(spt.Text + input),
+                _ => throw new ArgumentOutOfRangeException(nameof(text))
+            };
+        
+        public static SmartText operator +(string input, SmartText text)
+            => text switch
+            {
+                SmartEmbedText set => set with { PlainText = input + set.PlainText },
+                SmartPlainText spt => new SmartPlainText(input + spt.Text),
+                _ => throw new ArgumentOutOfRangeException(nameof(text))
+            };
         
         public static SmartText CreateFrom(string input)
         {