Switch to Changesets-based release process (#118)

* Switch to Changesets-based release process

* Bump version

* drop unused variable

* Update .github/workflows/version-or-publish.yml

Co-authored-by: Nicola Molinari <nicola.molinari@commercetools.com>

* Push also to a release line branch when releasing

* Change node version used in the version-or-publish workflow

* Switch to using the local action

Co-authored-by: Nicola Molinari <nicola.molinari@commercetools.com>

* build the action before trying to use it the workflow

* Add changeset and actually setup Changesets, lol

Co-authored-by: Nicola Molinari <nicola.molinari@commercetools.com>

.changeset/README.md

@@ -0,0 +1,8 @@
+# Changesets
+
+Hello and welcome! This folder has been automatically generated by `@changesets/cli`, a build tool that works
+with multi-package repos, or single-package repos to help you version and publish your code. You can
+find the full documentation for it [in our repository](https://github.com/changesets/changesets)
+
+We have a quick list of common questions to get you started engaging with this project in
+[our documentation](https://github.com/changesets/changesets/blob/main/docs/common-questions.md)

.changeset/config.json

@@ -0,0 +1,13 @@
+{
+  "$schema": "https://unpkg.com/@changesets/config@1.6.2/schema.json",
+  "changelog": [
+    "@changesets/changelog-github",
+    { "repo": "changesets/action" }
+  ],
+  "commit": false,
+  "linked": [],
+  "access": "restricted",
+  "baseBranch": "main",
+  "updateInternalDependencies": "patch",
+  "ignore": []
+}

.changeset/witty-walls-allow.md

@@ -0,0 +1,5 @@
+---
+"@changesets/action": major
+---
+
+From now on this action will be released using the Changesets-based workflow (using itself). Thanks to that we'll have a good release history. The users will be able to find specific versions of the action and will be able to track changes over time. It also improves the security as the build artifact will always get built in the CI environment, using a frozen lockfile.