Added loops section (google#1789)

This is a contribution of a loops section for Comprehensive Rust.

Author: mani-chand

src/SUMMARY.md

@@ -32,6 +32,8 @@
 - [Control Flow Basics](control-flow-basics.md)
   - [Conditionals](control-flow-basics/conditionals.md)
   - [Loops](control-flow-basics/loops.md)
+    - [`for`](control-flow-basics/loops/for.md)
+    - [`loop`](control-flow-basics/loops/loop.md)
   - [`break` and `continue`](control-flow-basics/break-continue.md)
   - [Blocks and Scopes](control-flow-basics/blocks-and-scopes.md)
   - [Functions](control-flow-basics/functions.md)

src/control-flow-basics/loops.md

@@ -22,42 +22,3 @@ fn main() {
     println!("Final x: {x}");
 }
 ```
-
-## `for`
-
-The [`for` loop](https://doc.rust-lang.org/std/keyword.for.html) iterates over
-ranges of values:
-
-```rust,editable
-fn main() {
-    for x in 1..5 {
-        println!("x: {x}");
-    }
-}
-```
-
-## `loop`
-
-The [`loop` statement](https://doc.rust-lang.org/std/keyword.loop.html) just
-loops forever, until a `break`.
-
-```rust,editable
-fn main() {
-    let mut i = 0;
-    loop {
-        i += 1;
-        println!("{i}");
-        if i > 100 {
-            break;
-        }
-    }
-}
-```
-
-<details>
-
-- We will discuss iteration later; for now, just stick to range expressions.
-- Note that the `for` loop only iterates to `4`. Show the `1..=5` syntax for an
-  inclusive range.
-
-</details>

src/control-flow-basics/loops/for.md

@@ -0,0 +1,20 @@
+# `for`
+
+The [`for` loop](https://doc.rust-lang.org/std/keyword.for.html) iterates over
+ranges of values:
+
+```rust,editable
+fn main() {
+    for x in 1..5 {
+        println!("x: {x}");
+    }
+}
+```
+
+<details>
+
+- We will discuss iteration later; for now, just stick to range expressions.
+- Note that the `for` loop only iterates to `4`. Show the `1..=5` syntax for an
+  inclusive range.
+
+</details>

src/control-flow-basics/loops/loop.md

@@ -0,0 +1,17 @@
+# `loop`
+
+The [`loop` statement](https://doc.rust-lang.org/std/keyword.loop.html) just
+loops forever, until a `break`.
+
+```rust,editable
+fn main() {
+    let mut i = 0;
+    loop {
+        i += 1;
+        println!("{i}");
+        if i > 100 {
+            break;
+        }
+    }
+}
+```