Make addCalligraphFonts protected, add javadoc

DEVSIX-2345

Author: LodrKumquat

src/main/java/com/itextpdf/html2pdf/resolver/font/DefaultFontProvider.java

@@ -127,7 +127,18 @@ private void addShippedFreeFonts(Range rangeToLoad) {
         }
     }
 
-    private Range addCalligraphFonts() {
+    /**
+     * This method loads a list of noto fonts from pdfCalligraph (if present in the classpath!) into FontProvider.
+     * The list is the following (each font is represented in regular and bold types): NotoSansArabic, NotoSansGurmukhi,
+     * NotoSansOriya, NotoSerifBengali, NotoSerifDevanagari, NotoSerifGujarati, NotoSerifHebrew, NotoSerifKannada,
+     * NotoSerifKhmer, NotoSerifMalayalam, NotoSerifTamil, NotoSerifTelugu, NotoSerifThai.
+     * If it's needed to have a DefaultFontProvider without typography fonts loaded,
+     * create an extension of DefaultFontProvider and override this method so it does nothing and only returns null.
+     *
+     * @return a unicode {@link Range} that excludes the loaded from pdfCalligraph fonts,
+     * i.e. the unicode range that is to be rendered with any other font contained in this FontProvider
+     */
+    protected Range addCalligraphFonts() {
         String methodName = "loadShippedFonts";
         Class<?> klass = null;
         try {