minor cleanup (OTF removed, bilbo font gone)

README.md

@@ -73,7 +73,7 @@ build/
         ...
         custom_theme_and_fonts.py
         custom_icon_theme_and_fonts.py
-        theme_buildter.py
+        theme_builder.py
     icons/
         icon1.png ...
 ```

cpp/custom_theme.hpp

@@ -20,11 +20,6 @@ enum class ThemeChoice {
     Fontawesome ///< The 'FontawesomeTheme' class
 };
 
-
-#pragma once
-
-#include <nanogui/theme.h>
-
 /*
 The JSON for this class::
 
@@ -96,8 +91,7 @@ class CustomTheme : public nanogui::Theme {
         mSpiraxFont = nanogui::createFontMem(ctx, "spirax", "Spirax-Regular.ttf");
         mMembraFont = nanogui::createFontMem(ctx, "membra", "membra.ttf");
 
-        // not forcing failure if mBilboFont is not loaded so that if Freetype was not
-        // found the application can still run
+        // -1 means font could not be loaded
         if (mSpiraxFont == -1 || mMembraFont == -1)
             throw std::runtime_error("Could not load the `spirax` or `membra` fonts!");