Update CHANGELOG.md.

Author: azriel91

CHANGELOG.md

@@ -2,6 +2,16 @@
 
 ## unreleased
 
-* Add `Dag::transitive_reduce` ([#36][#36]).
+* Add `Dag::transitive_reduce` ([#36][#36], [#41][#41]).
+* Add `Dag::{reserve_*, shrink_*}` functions ([#38][#38]).
+    - `reserve_nodes`
+    - `reserve_exact_nodes`
+    - `reserve_edges`
+    - `reserve_exact_edges`
+    - `shrink_to_fit`
+    - `shrink_to_fit_nodes`
+    - `shrink_to_fit_edges`
 
 [#36]: https://github.com/mitchmindtree/daggy/pull/36
+[#38]: https://github.com/mitchmindtree/daggy/pull/38
+[#41]: https://github.com/mitchmindtree/daggy/pull/41