Automated Changelog Entry for 6.4.0rc0 on master (#6058)

Co-authored-by: GitHub Action <41898282+github-actions[bot]@users.noreply.github.com>

CHANGELOG.md

@@ -14,12 +14,49 @@ Use `pip install pip --upgrade` to upgrade pip. Check pip version with
 
 <!-- <START NEW CHANGELOG ENTRY> -->
 
-## 6.4.0a1
+## 6.4.0rc0
 
-No merged PRs
+([Full Changelog](https://github.com/jupyter/notebook/compare/6.3.0...c19323de9ac56b2e0d075a3e6070be57ee63c194))
+
+### Bugs fixed
+
+- Fix Handling of Encoded Paths in Save As Dialog [#6030](https://github.com/jupyter/notebook/pull/6030) ([@afshin](https://github.com/afshin))
+- Fix: split_cell doesn't always split cell [#6017](https://github.com/jupyter/notebook/pull/6017) ([@gamestrRUS](https://github.com/gamestrRUS))
+
+### Maintenance and upkeep improvements
+
+- Revert "do not apply asyncio patch for tornado >=6.1" [#6052](https://github.com/jupyter/notebook/pull/6052) ([@minrk](https://github.com/minrk))
+- Use Jupyter Releaser [#6048](https://github.com/jupyter/notebook/pull/6048) ([@afshin](https://github.com/afshin))
+- Add Workflow Permissions for Lock Bot [#6042](https://github.com/jupyter/notebook/pull/6042) ([@jtpio](https://github.com/jtpio))
+- Fixes related to the recent changes in the documentation [#6021](https://github.com/jupyter/notebook/pull/6021) ([@frenzymadness](https://github.com/frenzymadness))
+
+### Documentation improvements
+
+- Spelling correction [#6045](https://github.com/jupyter/notebook/pull/6045) ([@wggillen](https://github.com/wggillen))
+- Minor typographical and comment changes [#6025](https://github.com/jupyter/notebook/pull/6025) ([@misterhay](https://github.com/misterhay))
+- Fixes related to the recent changes in the documentation [#6021](https://github.com/jupyter/notebook/pull/6021) ([@frenzymadness](https://github.com/frenzymadness))
+- Fix readthedocs environment [#6020](https://github.com/jupyter/notebook/pull/6020) ([@blink1073](https://github.com/blink1073))
+
+### Other merged PRs
+
+- Add maths checks in CSS reference test [#6035](https://github.com/jupyter/notebook/pull/6035) ([@stef4k](https://github.com/stef4k))
+- Correct 'Content-Type' headers [#6026](https://github.com/jupyter/notebook/pull/6026) ([@faucct](https://github.com/faucct))
+- Add Issue Lock and Answered Bots [#6019](https://github.com/jupyter/notebook/pull/6019) ([@afshin](https://github.com/afshin))
+- Fix skipped tests & remove deprecation warnings [#6018](https://github.com/jupyter/notebook/pull/6018) ([@befeleme](https://github.com/befeleme))
+- [Gateway] Track only this server's kernels [#5980](https://github.com/jupyter/notebook/pull/5980) ([@kevin-bates](https://github.com/kevin-bates))
+
+### Contributors to this release
+
+([GitHub contributors page for this release](https://github.com/jupyter/notebook/graphs/contributors?from=2021-03-22&to=2021-05-12&type=c))
+
+[@afshin](https://github.com/search?q=repo%3Ajupyter%2Fnotebook+involves%3Aafshin+updated%3A2021-03-22..2021-05-12&type=Issues) | [@befeleme](https://github.com/search?q=repo%3Ajupyter%2Fnotebook+involves%3Abefeleme+updated%3A2021-03-22..2021-05-12&type=Issues) | [@blink1073](https://github.com/search?q=repo%3Ajupyter%2Fnotebook+involves%3Ablink1073+updated%3A2021-03-22..2021-05-12&type=Issues) | [@faucct](https://github.com/search?q=repo%3Ajupyter%2Fnotebook+involves%3Afaucct+updated%3A2021-03-22..2021-05-12&type=Issues) | [@frenzymadness](https://github.com/search?q=repo%3Ajupyter%2Fnotebook+involves%3Afrenzymadness+updated%3A2021-03-22..2021-05-12&type=Issues) | [@gamestrRUS](https://github.com/search?q=repo%3Ajupyter%2Fnotebook+involves%3AgamestrRUS+updated%3A2021-03-22..2021-05-12&type=Issues) | [@jtpio](https://github.com/search?q=repo%3Ajupyter%2Fnotebook+involves%3Ajtpio+updated%3A2021-03-22..2021-05-12&type=Issues) | [@kevin-bates](https://github.com/search?q=repo%3Ajupyter%2Fnotebook+involves%3Akevin-bates+updated%3A2021-03-22..2021-05-12&type=Issues) | [@minrk](https://github.com/search?q=repo%3Ajupyter%2Fnotebook+involves%3Aminrk+updated%3A2021-03-22..2021-05-12&type=Issues) | [@misterhay](https://github.com/search?q=repo%3Ajupyter%2Fnotebook+involves%3Amisterhay+updated%3A2021-03-22..2021-05-12&type=Issues) | [@stef4k](https://github.com/search?q=repo%3Ajupyter%2Fnotebook+involves%3Astef4k+updated%3A2021-03-22..2021-05-12&type=Issues) | [@wggillen](https://github.com/search?q=repo%3Ajupyter%2Fnotebook+involves%3Awggillen+updated%3A2021-03-22..2021-05-12&type=Issues)
 
 <!-- <END NEW CHANGELOG ENTRY> -->
 
+## 6.4.0a1
+
+No merged PRs
+
 ## 6.4.0a0
 
 No merged PRs