update changelog

Author: blink1073

CHANGELOG.md

@@ -1,5 +1,47 @@
 # Changelog
 
+## 2021-4-27
+
+([Full Changelog](https://github.com/jupyterlab/lumino/compare/2012.4.19...f4d7e30f37e3bb362b89865a6ce24779c11e91bc))
+
+    @lumino/algorithm: 1.5.0 => 1.6.0
+    @lumino/application: 1.18.0 => 1.19.0
+    @lumino/collections: 1.5.0 => 1.6.0
+    @lumino/commands: 1.14.0 => 1.15.0
+    @lumino/coreutils: 1.7.0 => 1.8.0
+    @lumino/datagrid: 0.22.0 => 0.23.0
+    @lumino/datastore: 0.13.0 => 0.14.0
+    @lumino/default-theme: 0.12.0 => 0.13.0
+    @lumino/disposable: 1.6.0 => 1.7.0
+    @lumino/domutils: 1.4.0 => 1.5.0
+    @lumino/dragdrop: 1.9.0 => 1.10.0
+    @lumino/keyboard: 1.4.0 => 1.5.0
+    @lumino/messaging: 1.6.0 => 1.7.0
+    @lumino/polling: 1.5.0 => 1.6.0
+    @lumino/properties: 1.4.0 => 1.5.0
+    @lumino/signaling: 1.6.0 => 1.7.0
+    @lumino/virtualdom: 1.10.0 => 1.11.0
+    @lumino/widgets: 1.21.0 => 1.22.0
+
+### Bugs fixed
+
+- Normalize frequency max to respect interval at instantiation time [#177](https://github.com/jupyterlab/lumino/pull/177) ([@afshin](https://github.com/afshin))
+
+### Documentation improvements
+
+- Fix a minor typo in comment [#176](https://github.com/jupyterlab/lumino/pull/176) ([@cnydw](https://github.com/cnydw))
+
+### Other merged PRs
+
+- Switch back to TypeScript 3.6 [#175](https://github.com/jupyterlab/lumino/pull/175) ([@jtpio](https://github.com/jtpio))
+- Fix tabindex for menu bar [#174](https://github.com/jupyterlab/lumino/pull/174) ([@marthacryan](https://github.com/marthacryan))
+
+### Contributors to this release
+
+([GitHub contributors page for this release](https://github.com/jupyterlab/lumino/graphs/contributors?from=2021-04-19&to=2021-04-27&type=c))
+
+[@afshin](https://github.com/search?q=repo%3Ajupyterlab%2Flumino+involves%3Aafshin+updated%3A2021-04-19..2021-04-27&type=Issues) | [@cnydw](https://github.com/search?q=repo%3Ajupyterlab%2Flumino+involves%3Acnydw+updated%3A2021-04-19..2021-04-27&type=Issues) | [@jtpio](https://github.com/search?q=repo%3Ajupyterlab%2Flumino+involves%3Ajtpio+updated%3A2021-04-19..2021-04-27&type=Issues) | [@marthacryan](https://github.com/search?q=repo%3Ajupyterlab%2Flumino+involves%3Amarthacryan+updated%3A2021-04-19..2021-04-27&type=Issues) | [@sccolbert](https://github.com/search?q=repo%3Ajupyterlab%2Flumino+involves%3Asccolbert+updated%3A2021-04-19..2021-04-27&type=Issues) | [@welcome](https://github.com/search?q=repo%3Ajupyterlab%2Flumino+involves%3Awelcome+updated%3A2021-04-19..2021-04-27&type=Issues)
+
 ## 2021-4-19
 
 ([Full Changelog](https://github.com/jupyterlab/lumino/compare/2021.4.12...fc0c0ddf950d38e957bfd1e076ffb937a679009f))