add e2e test docs

Author: CodingWizKid

Makefile

@@ -53,6 +53,9 @@ html-coverage: out/report.json
 out/report.json:
 	go test -race ./... -coverprofile=out/cover.out --json | tee "$(@)"
 
+test-e2e:
+	@STACKIT_TOKEN=$(STACKIT_TOKEN) TEST_ZONE_NAME=$(TEST_ZONE_NAME) go test -race -tags=e2e ./... -coverprofile out/cover.out
+
 run:
 	go run cmd/main.go
 

e2e_test/README.md

@@ -0,0 +1,49 @@
+# End-to-End (E2E) Test Suite
+
+This repository segment encapsulates the comprehensive E2E testing procedures for this project module. It harnesses the `fixture.RunConformance` method to execute conformity verification sequences, ensuring adherence to `cert-manager` established protocols.
+
+## Test Execution Workflow
+
+### Environmental Prerequisite Configuration:
+For appropriate test initialization within the STACKIT ecosystem, it is imperative to align the environment with 
+the predetermined specifications. STACKIT dictates a structural model where a parent project umbrellas various 
+resource entities, inclusive of DNS zones.
+
+1. **Project Identification Parameterization**:   
+Configure the unique `project_id` in the [configuration manifest](../testdata/stackit/config.json). Typical configuration appears as:
+    ```json
+    {
+      "projectId": "c242332a-ae82-42e2-80e8-eed338fd2b2f",
+      "authTokenSecretNamespace": "default"
+    }
+    ```
+
+    This instantiation assumes the existence of the specified project, and the associated authentication 
+    token possesses requisite privileges for project and zone access.
+2. **Authentication Token Configuration**:    
+Establish an environment variable for the authentication token, duly vested with CRUD permissions for DNS zones:
+    ```bash
+    export STACKIT_TOKEN="<your-token>"
+    ```
+3. **Zone Initialization**:   
+Declare the testing DNS zone. Ensure project_id consistency:
+    ```bash
+    export TEST_ZONE_NAME="test-zone.runs.onstackit.cloud"
+    ```
+    Invoke the following HTTP request to either instantiate a fresh zone or validate the existing one:
+    ```bash
+    curl --location "https://dns.api.stackit.cloud/v1/projects/c242332a-ae82-42e2-80e8-eed338fd2b2f/zones" \
+    --header 'Content-Type: application/json' \
+    --header "Authorization: Bearer $AUTHENTICATION_TOKEN" \
+    --data '{
+        "name": "cert manager e2e test",
+        "dnsName": "$TEST_ZONE_NAME" 
+    }'
+    ```
+    Post successful invocation, validate zone ownership. For pre-existing zones, consider a unique zone parameter.
+
+### Environmental Prerequisite Configuration:
+With prerequisites addressed, proceed to run the entire E2E test suite:
+```bash
+make test-e2e
+```