feat: add Bookerly font plugin with style selection and SmallerFonts integration

plugins/bookerly/BookerlyPlugin.h

@@ -0,0 +1,14 @@
+#pragma once
+
+#include <Arduino.h>
+
+enum class BookerlyStyle : uint8_t {
+    REGULAR     = 0,
+    ITALIC      = 1,
+    BOLD        = 2,
+    BOLD_ITALIC = 3,
+};
+
+namespace BookerlyPlugin {
+    const char* styleName(BookerlyStyle style);
+}