chore: update release-notes

release-notes/4.13.0.md

@@ -20,20 +20,33 @@ Thanks to @Evertt for making the case for this feature.
 
 ### Command parser
 
-It's an often requested feature to be able to parse command arguments. As of this release, `ctx.command` and `ctx.args` are available for this usecase. It's only available in `bot.command` handlers.
+It's an often requested feature to be able to parse command arguments.
 
-`ctx.command` is the matched command (even if you used RegExp), and it does not include the botname if it was included in the user's command. `ctx.args` is a parsed list of arguments passed to it. Have a look at the example:
+As of this release, `ctx.command`, `ctx.payload`, and `ctx.args` are available for this usecase. It's only available in `bot.command` handlers.
+
+`ctx.command` is the matched command (even if you used RegExp), and it does not include the botname if it was included in the user's command. `ctx.payload` is the unparsed text part excluding the command. `ctx.args` is a parsed list of arguments passed to it. Have a look at the example:
 
 ```TS
 // User sends /warn --delete "Offtopic chat"
 
 bot.command("warn", async ctx => {
-  ctx.command; // [ "warn" ]
   ctx.args; // [ "--delete", "Offtopic chat" ]
+
+  ctx.command; // [ "warn" ]
+  ctx.payload; // "--delete \"Offtopic chat\""
 });
 ```
 
-`ctx.args` is considered unstable, and the parser is subject to fine-tuning and improvements based on user feedback.
+⚠️ `ctx.args` is still considered unstable, and the parser is subject to fine-tuning and improvements based on user feedback.
+
+The more generic `ctx.payload` for all commands causes `ctx.startPayload` in `bot.start` to be redundant, and hence the latter is now deprecated.
+
+```diff
+bot.start(ctx => {
+- console.log(ctx.startPayload);
++ console.log(ctx.payload);
+});
+```
 
 You can also play with this feature by importing the parser directly: