release: docs for v0.20.1 (#401)

## Description

<!-- 
Please do not leave this blank 
This PR [adds/removes/fixes/replaces] the [feature/bug/etc]. 
-->

Please include a summary of the changes and the related issue. Please
also include relevant motivation and context. List any dependencies that
are required for this change.


## What type of PR is this? (check all applicable)

- [ ] 🍕 Feature
- [ ] 🐛 Bug Fix
- [ ] 📝 Documentation Update
- [ ] 🎨 Style
- [ ] 🧑‍💻 Code Refactor
- [ ] 🔥 Performance Improvements
- [ ] ✅ Test
- [ ] 🤖 Build
- [ ] 🔁 CI
- [ ] 📦 Chore (Release)
- [ ] ⏩ Revert

## Related Tickets & Documents

<!-- 
Please use this format link issue numbers: Fixes #123

https://docs.github.com/en/free-pro-team@latest/github/managing-your-work-on-github/linking-a-pull-request-to-an-issue#linking-a-pull-request-to-an-issue-using-a-keyword
-->
- Related Issue # (issue)
- Closes # (issue)
- Fixes # (issue)
> Remove if not applicable

## Screenshots

<!-- Visual changes require screenshots -->


## Added tests?

- [ ] 👍 yes
- [ ] 🙅 no, because they aren't needed
- [ ] 🙋 no, because I need help
- [ ] Separate ticket for tests # (issue/pr)

Please describe the tests that you ran to verify your changes. Provide
instructions so we can reproduce. Please also list any relevant details
for your test configuration


## Added to documentation?

- [ ] 📜 README.md
- [ ] 🙅 no documentation needed

## Checklist:

- [ ] My code follows the style guidelines of this project
- [ ] I have performed a self-review of my code
- [ ] I have commented my code, particularly in hard-to-understand areas
- [ ] I have made corresponding changes to the documentation
- [ ] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my
feature works
- [ ] New and existing unit tests pass locally with my changes
- [ ] Any dependent changes have been merged and published in downstream
modules

docs/release_notes/v0.20.1.md

@@ -0,0 +1,3 @@
+# Release 0.21.0
+
+- fix: Quick hack to address issue 68 - snapshot tag doesn't meet strict semver check (#390)

pkg/version/release.go

@@ -5,7 +5,7 @@
 package version
 
 // ReleaseVersion is the version number in semver format "vX.Y.Z", prefixed with "v".
-var ReleaseVersion = "v0.20.0"
+var ReleaseVersion = "v0.20.1"
 
 // ReleaseCandidate is the release candidate ID in format "rc.X", which will be appended to the release version.
 var ReleaseCandidate = "rc.1"