website: Mention that it is generated.

Makefile

@@ -5,7 +5,8 @@ favicon:
 
 website:
 	cat try.html | sed "s,<img src='/,&/img.shields.io/," \
-             | sed "s,<span id='imgUrlPrefix'>,&http://img.shields.io," > index.html
+             | sed "s,<span id='imgUrlPrefix'>,&http://img.shields.io," \
+	     | sed "s,<style>,<!-- Warning: this file was generated from try.html -->\n<style>," > index.html
 
 deploy:
 	git add -f Verdana.ttf

index.html

@@ -4,6 +4,7 @@
 <meta name='viewport' content='width=device-width,initial-scale=1'>
 <link rel='icon' type='image/png' href='favicon.png'>
 <link href='//fonts.googleapis.com/css?family=Vollkorn' rel='stylesheet'>
+<!-- Warning: this file was generated from try.html -->
 <style>
 :root { text-align: center; font-family: Linux Libertine O, Vollkorn, serif; }
 code { white-space: pre-wrap; }