Merge pull request airbnb#70 from tderflinger/master

Update README.md

Author: ljharb

README.md

@@ -310,6 +310,7 @@ If you must use an ID selector in the first place (and you should really try not
   - ![es](https://raw.githubusercontent.com/gosquared/flags/master/flags/flags/shiny/24/Spain.png) **Spanish**: [ismamz/guia-de-estilo-css](https://github.com/ismamz/guia-de-estilo-css)
   - ![vn](https://raw.githubusercontent.com/gosquared/flags/master/flags/flags/shiny/24/Vietnam.png) **Vietnamese**: [trungk18/css-style-guide](https://github.com/trungk18/css-style-guide)
   - ![vn](https://raw.githubusercontent.com/gosquared/flags/master/flags/flags/shiny/24/Italy.png) **Italian**: [antoniofull/linee-guida-css](https://github.com/antoniofull/linee-guida-css)
+  - ![de](https://raw.githubusercontent.com/gosquared/flags/master/flags/flags/shiny/24/Germany.png) **German**: [tderflinger/css-styleguide](https://github.com/tderflinger/css-styleguide)
 
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