Update CHANGELOG.md and entry.dart

CHANGELOG.md

@@ -4,6 +4,7 @@ All notable changes to this project will be documented in this file.
 ## [Unreleased]
 ### Changed
 - upgraded Flutter to stable v2.5.0
+- faster collection loading when launching the app
 
 ## [v1.5.1] - 2021-09-08
 ### Added

lib/model/entry.dart

@@ -339,11 +339,13 @@ class AvesEntry {
     _bestDate = null;
   }
 
+  // TODO TLAD cache _monthTaken
   DateTime? get monthTaken {
     final d = bestDate;
     return d == null ? null : DateTime(d.year, d.month);
   }
 
+  // TODO TLAD cache _dayTaken
   DateTime? get dayTaken {
     final d = bestDate;
     return d == null ? null : DateTime(d.year, d.month, d.day);