added instructions for version bump

DEVELOPER.md

@@ -3,3 +3,43 @@
 ## Version bump
 
 Version is changed in src/damaris/__init__.py
+
+### Process
+
+1. Update the version in `src/damaris/__init__.py`
+2. Add a new changelog entry in `debian/changelog` using the `dch` (debchange) tool
+
+### Using dch tool
+
+The `dch` tool (from the `devscripts` package) is the standard way to maintain debian changelog files. Example workflow:
+
+```bash
+# Update version in Python package
+sed -i 's/__version__ = "0.24"/__version__ = "0.25"/' src/damaris/__init__.py
+
+# Add changelog entry with dch
+dch --newversion 0.25
+
+# This opens your editor to add the changes for this version
+# Or use batch mode with message:
+dch -v 0.25 "New features and bug fixes"
+
+# Verify the changelog
+tail -20 debian/changelog
+```
+
+The `dch` command will:
+- Create a new entry with the specified version
+- Set the distribution to "stable" (or "unstable" for development versions)
+- Use the maintainer name and email from the previous entry or environment variables
+- Open your editor to add the change descriptions
+
+For development versions, use:
+```bash
+dch -v 0.25-1 --distribution unstable "Development version"
+```
+
+Remember to install devscripts if needed:
+```bash
+sudo apt-get install devscripts
+```