[EK-1139] Update README, add specs to workflow

.github/workflows/rails.yml

@@ -40,3 +40,20 @@ jobs:
 
       - name: Run Brakeman
         run: bundle exec brakeman
+  specs:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: 3.3.3
+          bundler-cache: true
+
+      - name: Generate dummy app
+        run: bundle exec rake test_app
+
+      - name: Run RSpec
+        run: bundle exec rspec

README.md

@@ -2,6 +2,11 @@
 
 **Spree-spl** is a plugin that provides a promotion switcher for Spree, enabling enhanced loyalty program functionality.
 
+## Compatibility
+### Versions <= 1.7.x
+Are compatible with Spree ~> 4.x and Rails <= 7.2
+### Versions > 1.7 (current master branch, check current state)
+Is compatible with Spree ~> 5.2, and Rails >= 7.0, < 8.3
 ## Installation
 
 Add spree-spl to your Gemfile and run bundle install: