Update readme

Author: psmyrdek

README.md

@@ -1,4 +1,51 @@
 # GPT Debugger
 
+Debug flaky CI/CD pipelines with GPT-4.
+
+## Inputs
+
+- `OPENAI_API_KEY` - OpenAI API key. You can get it from [OpenAI](https://platform.openai.com/account/api-keys).
+
+## How to
+
+1. Redirect `stderr` of one of your steps to `gpt_error.log` file:
+2. Add new step to your workflow and mark it with either `always()` or `failure()` expression:
+
+```yaml
+jobs:
+  tests:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Run e2e
+        id: e2e
+        run: npm run e2e 2> gpt_error.log
+
+      - uses: przeprogramowani/gpt-debugger@main
+        if: ${{ failure() }}
+        with:
+          OPENAI_API_KEY: ${{ secrets.OPENAI_API_KEY }}
+```
+
+## Output
+
+Example output from the action:
+
+```txt
+🧑‍⚕️ Presenting GPT-4 issue analysis:
+
+The error indicates that an "e2e" script is expected but not defined in the package.json file. To fix this issue, ensure you have an "e2e" script specified in your package.json file under the "scripts" section. If your intention was to run end-to-end tests, you might need something like:
+
+"scripts": {
+"e2e": "your-e2e-test-command here"
+}
+
+Replace "your-e2e-test-command here" with the actual command you use to run your end-to-end tests.
+
+Relevant file:
+- package.json
+```
+
+## Authors
+
 - [Przeprogramowani](https://przeprogramowani.pl)
 - [Opanuj Frontend](https://opanujfrontend.pl)