[move book] Adding docs for 2.1 language release

Adds loop label documentation and updates the release notes.

apps/nextra/pages/en/build/smart-contracts/book/_meta.tsx

@@ -2,8 +2,8 @@ export default {
   SUMMARY: {
     title: "Summary",
   },
-  "move-2.0": {
-    title: "Move 2.0 Release Notes",
+  "move-2": {
+    title: "Move 2 Release Notes",
   },
   "---getting-started---": {
     type: "separator",

apps/nextra/pages/en/build/smart-contracts/book/loops.mdx

@@ -259,3 +259,28 @@ script {
   }
 }
 ```
+
+## Loop Labels
+
+_Since language version 2.1_
+
+A `while` or `loop` statement can have a label which can be referred to by a `break` or `continue` statement. In the presence of nested loops, this allows to refer to outer loops. Example:
+
+```move
+script {
+  fun example(x: u64): u64 {
+    'label1: while (x > 10) {
+      loop {
+        if (x % 2 == 0) {
+          x -= 1;
+          continue 'label1;
+        } else if (x < 10) {
+          break 'label1
+        } else
+          x -= 2
+      }
+    };
+    x
+  }
+}
+```

apps/nextra/pages/en/build/smart-contracts/compiler_v2.mdx

@@ -6,7 +6,7 @@ title: "Move On Aptos Compiler (beta)"
 
 The Move on Aptos compiler (codename 'compiler v2') is a new tool which translates Move source code into Move bytecode. It unifies the architectures of the Move compiler and the Move Prover, enabling faster innovation in the Move language. It also offers new tools for defining code optimizations which can be leveraged to generate more gas efficient code for Move programs.
 
-The new compiler supports Move 2, the latest revision of the Move language. Head over to the [release page in the book](book/move-2.0.mdx) to learn more about the new features in Move 2. You can select both this language version and the new compiler by using `aptos move compile --move-2`.
+The new compiler supports Move 2, the latest revision of the Move language. Head over to the [release page in the book](book/move-2.mdx) to learn more about the new features in Move 2. You can select both this language version and the new compiler by using `aptos move compile --move-2`.
 
 ## Compiler v2 Release State
 
@@ -37,4 +37,4 @@ To run compiler v2 and Move 2, pass the flag `--move-2` to the Aptos CLI. Exampl
 aptos move compile --move-2
 aptos move test --move-2
 aptos move prove --move-2
-```
+```