Add numbering manually

Signed-off-by: Felipe R. Monteiro <[email protected]>

doc/src/SUMMARY.md

@@ -13,16 +13,16 @@
 ---
 
 - [Challenges](./challenges.md)
-   1. [Core Transmutation](./challenges/0001-core-transmutation.md)
-   2. [Memory safety of core intrinsics](./challenges/0002-intrinsics-memory.md)
-   3. [Pointer Arithmetic](./challenges/0003-pointer-arithmentic.md)
-   4. [Memory safety of BTreeMap's `btree::node` module](./challenges/0004-btree-node.md)
-   5. [Inductive data type](./challenges/0005-linked-list.md)
-   6. [Safety of NonNull](./challenges/0006-nonnull.md)
-   7. [--](./challenges/0007-.md)
-   8. [Contracts for SmallSort](./challenges/0008-smallsort.md)
-   9. [Safe abstractions for `core::time::Duration`](./challenges/0009-duration.md)
-   10. [Memory safety of String](./challenges/0010-string.md)
-   11. [Safety of Methods for Numeric Primitive Types](./challenges/0011-floats-ints.md)
-   12. [Safety of NonZero](./challenges/0012-nonzero.md)
+  - [1: Verify core transmuting methods](./challenges/0001-core-transmutation.md)
+  - [2: Verify the memory safery of core intrinsics using raw pointers](./challenges/0002-intrinsics-memory.md)
+  - [3: Verifying Raw Pointer Arithmetic Operations](./challenges/0003-pointer-arithmentic.md)
+  - [4: Memory safety of BTreeMap's `btree::node` module](./challenges/0004-btree-node.md)
+  - [5: Verify functions iterating over inductive data type: `linked_list`](./challenges/0005-linked-list.md)
+  - [6: Safety of `NonNull`](./challenges/0006-nonnull.md)
+  - [8: Contracts for SmallSort](./challenges/0008-smallsort.md)
+  - [9: Safe abstractions for `core::time::Duration`](./challenges/0009-duration.md)
+  - [10: Memory safety of String](./challenges/0010-string.md)
+  - [11: Safety of Methods for Numeric Primitive Types](./challenges/0011-floats-ints.md)
+  - [12: Safety of `NonZero`](./challenges/0012-nonzero.md)
+