Apply suggestions from code review

Co-authored-by: Erik Sundell <[email protected]>

Author: minrk

RELEASE.md

@@ -94,7 +94,7 @@ Also the images we build are based on some image specified in the `FROM` stateme
   - [ ] Set the next prerelease version (don't create a tag).
 
     ```bash
-    tbump --no-tag x.y+1.z-0.dev
+    tbump --no-tag x.y.z+1-0.dev
     ```
 
   - [ ] Create a GitHub release.

dev-requirements.txt

@@ -5,7 +5,7 @@
 #
 # ref: https://github.com/jupyterhub/chartpress
 #
-chartpress==2.*
+chartpress>=2.1,<3
 
 # pytest run tests that require requests and pyyaml
 pytest>=3.7.1

tbump.toml

@@ -1,4 +1,9 @@
-# tbump config sets baseVersion in chartpress.yaml
+# tbump is a tool to update version fields that we use
+# to update baseVersion in chartpress.yaml as documented
+# in RELEASE.md
+#
+# Config reference: https://github.com/your-tools/tbump#readme
+#
 [version]
 current = "2.0.0-beta.1"