Fix CHANGELOG so that we can note backported patches.

(cherry picked from commit 64099e9adf)
Signed-off-by: Isis Lovecruft <isis@patternsinthevoid.net>

CHANGELOG.md

@@ -1,12 +1,15 @@
 # Changelog
 
-Entries are listed in reverse chronological order.
+Entries are listed in reverse chronological order per undeprecated
+major series.
 
-## 2.1.0
+## 2.x series
+
+### 2.1.0
 
 * Make `Scalar::from_bits` a `const fn`, allowing its use in `const` contexts.
 
-## 2.0.0
+### 2.0.0
 
 * Fix a data modeling error in the `serde` feature pointed out by Trevor Perrin
   which caused points and scalars to be serialized with length fields rather
@@ -25,7 +28,15 @@ Entries are listed in reverse chronological order.
 The only significant change is the data model change to the `serde` feature;
 besides the `rand_core` version bump, there are no other user-visible changes.
 
-## 1.2.3
+## 1.x series
+
+### 1.2.4
+
+* Specify a semver bound for `clear_on_drop` rather than an exact version,
+  addressing an issue where changes to inline assembly in rustc prevented
+  `clear_on_drop` from working without an update.
+
+### 1.2.3
 
 * Fix an issue identified by a Quarkslab audit (and Jack Grigg), where manually
   constructing unreduced `Scalar` values, as needed for X/Ed25519, and then
@@ -39,14 +50,14 @@ besides the `rand_core` version bump, there are no other user-visible changes.
 * Fix compilation on nightly broken due to changes to the `#[doc(include)]` path
   root (not quite correctly done in 1.2.2).
 
-## 1.2.2
+### 1.2.2
 
 * Fix a typo in an internal doc-comment.
 * Add the "crypto" tag to crate metadata.
 * Fix compilation on nightly broken due to changes to the `#[doc(include)]` path
   root.
 
-## 1.2.1
+### 1.2.1
 
 * Fix a bug in bucket index calculations in the Pippenger multiscalar algorithm
   for very large input sizes.
@@ -55,7 +66,7 @@ besides the `rand_core` version bump, there are no other user-visible changes.
 * Ensure that that multiscalar and NAF computations work correctly on extremal
   `Scalar` values constructed via `from_bits`.
 
-## 1.2.0
+### 1.2.0
 
 * New multiscalar multiplication algorithm with better performance for
   large problem sizes.  The backend algorithm is selected
@@ -64,16 +75,16 @@ besides the `rand_core` version bump, there are no other user-visible changes.
 * Equality of Edwards points is now checked in projective coordinates.
 * Serde can now be used with `no_std`.
 
-## 1.1.4
+### 1.1.4
 
 * Fix typos in documentation comments.
 * Remove unnecessary `Default` bound on `Scalar::from_hash`.
 
-## 1.1.3
+### 1.1.3
 
 * Reverts the change in 1.1.0 to allow owned and borrowed RNGs, which caused a breakage due to a subtle interaction with ownership rules.  (The `RngCore` change is retained).
 
-## 1.1.2
+### 1.1.2
 
 * Disabled KaTeX on `docs.rs` pending proper [support upstream](https://github.com/rust-lang/docs.rs/issues/302).
 
@@ -81,7 +92,7 @@ besides the `rand_core` version bump, there are no other user-visible changes.
 
 * Fixed an issue related to `#[cfg(rustdoc)]` which prevented documenting multiple backends.
 
-## 1.1.0
+### 1.1.0
 
 * Adds support for precomputation for multiscalar multiplication.
 * Restructures the internal source tree into `serial` and `vector` backends (no change to external API).
@@ -90,19 +101,19 @@ besides the `rand_core` version bump, there are no other user-visible changes.
 * Replaces the `rand` dependency with `rand_core`.
 * Generalizes trait bounds on `RistrettoPoint::random()` and `Scalar::random()` to allow owned and borrowed RNGs and to allow `RngCore` instead of `Rng`.
 
-## 1.0.3
+### 1.0.3
 
 * Adds `ConstantTimeEq` implementation for compressed points.
 
-## 1.0.2
+### 1.0.2
 
 * Fixes a typo in the naming of variables in Ristretto formulas (no change to functionality).
 
-## 1.0.1
+### 1.0.1
 
 * Depends on the stable `2.0` version of `subtle` instead of `2.0.0-pre.0`.
 
-## 1.0.0
+### 1.0.0
 
 Initial stable release.  Yanked due to a dependency mistake (see above).