Update README.md with changesets description (#1094)

update readme

README.md

@@ -196,6 +196,14 @@ SKIP_NX_CACHE=true make test
 
 To run Chromatic (for visual regression testing) on a PR, add the `run_chromatic` label to the PR in Github. The Chromatic tests are required to pass by CI, so this will _need_ to be done at least once before a PR is merged. We recommend you only add the label once you are happy with any changes made and have checked for visual regressions manually first.
 
+### Releasing a package
+
+Libs within CSNX are available as NPM packages. We use [Changesets](<[url](https://github.com/changesets/changesets)>) to automate this release process.
+
+To publish your changes to NPM, run `make changeset`. This will open the Changesets CLI, and you will be offered a list of packages to release. Once you've selected the changed package/s you'll be given the option of `major`, `minor` or `patch` release. Select one of these and add a description.
+
+This will create a "changeset": a `.md` file containing the release information. When you merge your branch, the changeset will be picked up by the Changests GHA, which will in turn create a release PR. To complete the NPM release merge this second PR.
+
 ## Troubleshooting
 
 ### Unable to commit