[add] better error handling, [add] font selector, [add] tailwind generation

utils/utils_test.go

@@ -0,0 +1,12 @@
+package utils
+
+import "testing"
+
+func TestCalculatePartialPD5(t *testing.T) {
+	partialMD5, err := CalculatePartialMD5("../_test_files/alice.epub")
+
+	want := "386d1cb51fe4a72e5c9fdad5e059bad9"
+	if partialMD5 != want {
+		t.Fatalf(`Expected: %v, Got: %v, Error: %v`, want, partialMD5, err)
+	}
+}