Update 'Sustainable Web Dev'

Sustainable-Web-Dev.md

@@ -1,9 +1,26 @@
+
 ### 'Sustainable' Web Dev
 
-* [zero carbon websites](https://kinsta.com/blog/zero-carbon-websites/)
+_Tools_
 
-* [Website Carbon Calculator](https://www.websitecarbon.com/)
+* [Calculating Digital Emissions](https://sustainablewebdesign.org/calculating-digital-emissions/)
+* [Ecograder](https://ecograder.com/)
+* [Website Footprint](https://www.website-footprint.com/en/)
 
-* [Sustainable Web Design Community Group](https://www.w3.org/community/sustyweb/)
+_Design Resources_
+
+* [Lowtechmag WebDesign](https://github.com/lowtechmag/solar/wiki/Solar-Web-Design)
+* [BBC planet 4 Design System](https://p4-designsystem.greenpeace.org/05f6e9516/p/76cd7b-planet-4-design-system)
+* [w3 Community SustyWeb](https://www.w3.org/community/sustyweb/)
+* [Sustainable Digital Design](https://sustainabledigitaldesign.com/)
+
+
+_Optimizing for Web Sustainability_
+
+* [Image srcset](https://www.w3schools.com/TAgs/att_source_srcset.asp)
+* [Web Fonts](https://www.w3schools.com/cssref/css_websafe_fonts.asp)
+* [WOFF2](https://developer.mozilla.org/en-US/docs/Web/Guide/WOFF)
+* [Webfont Generator](https://www.fontsquirrel.com/tools/webfont-generator)
+* [Variable Fonts](https://v-fonts.com/)
+* [Subsetting fonts](https://everythingfonts.com/subsetter)
 
-* [Resilient Web Design](https://resilientwebdesign.com/)