web fonts for properly rendering multilingual website

When creating a website on github pages with text in English, Hindi and Telugu, the first attempt was to just copy-paste the content from a Google Doc exported as HTML. But that had two problems.

1. The text was represented as characters like अंग्रेजी
   not human-readable for easy editing.
   
   
2. Firefox was not rendering some of the characters properly, like
   
   instead of

   

   
   
   So, tried incorporating web-fonts - reading up
   
   https://teck.in/free-google-web-fonts-for-indian-languages.html
   https://fonts.google.com/knowledge/using_type/using_web_fonts
   https://www.zachleat.com/web/css-tricks-web-fonts/
   https://www.w3schools.com/css/css3_fonts.asp
    
   Google's free multilingual font Noto Sans was what I used. 
   
   
   CSS like
   @font-face {
               font-family: EnglishBold;
               src: url(images/notosans-black.ttf);
           }
   
           .eng {
               font-family: EnglishRegular;
           }