feat(refacto): move everything in internal package

This allows to install katenary with `go install` and to clean up the
project folder.

internal/generator/extrafiles/readme_test.go

@@ -0,0 +1,33 @@
+package extrafiles
+
+import (
+	"regexp"
+	"testing"
+)
+
+func TestReadMeFile_Basic(t *testing.T) {
+	values := map[string]any{
+		"replicas": 2,
+		"image": map[string]any{
+			"repository": "nginx",
+			"tag":        "latest",
+		},
+	}
+
+	result := ReadMeFile("testchart", "A test chart", values)
+	t.Logf("Generated README content:\n%s", result)
+	paramerRegExp := regexp.MustCompile(`\|\s+` + "`" + `(.*?)` + "`" + `\s+\|\s+` + "`" + `(.*?)` + "`" + `\s+\|`)
+	matches := paramerRegExp.FindAllStringSubmatch(result, -1)
+	if len(matches) != 3 {
+		t.Errorf("Expected 5 lines in the table for headers and parameters, got %d", len(matches))
+	}
+	if matches[0][1] != "image.repository" || matches[0][2] != "nginx" {
+		t.Errorf("Expected third line to be image.repository, got %s", matches[1])
+	}
+	if matches[1][1] != "image.tag" || matches[1][2] != "latest" {
+		t.Errorf("Expected fourth line to be image.tag, got %s", matches[2])
+	}
+	if matches[2][1] != "replicas" || matches[2][2] != "2" {
+		t.Errorf("Expected second line to be replicas, got %s", matches[0])
+	}
+}