doc: Do not explicitly provide Google fonts

Simplify doc build by dropping fonts from repository. If the fonts are
not installed on the system, the browser will simply use fallback fonts
which seems like an ok tradeoff.

doc/css/styles.css

@@ -1,5 +1,4 @@
 /* Sligthly modified Asciidoctor default stylesheet | MIT License | http://asciidoctor.org */
-@import "fonts/fonts.css";
 article,aside,details,figcaption,figure,footer,header,hgroup,main,nav,section,summary{display:block}
 audio,canvas,video{display:inline-block}
 audio:not([controls]){display:none;height:0}

doc/doc.mk

@@ -18,8 +18,6 @@ build-doc:
 	  --indent=none \
 	  --shorten-ids
 
-	cp -a --reflink=auto doc/fonts doc/html
-
 	asciidoctor doc/index -o doc/html/index.html
 
 clean: clean-doc

doc/fonts/fonts.css

@@ -1,66 +0,0 @@
-@font-face {
-  font-family: 'Droid Sans Mono';
-  font-style: normal;
-  font-weight: 400;
-  src: local('Droid Sans Mono Regular'), local('DroidSansMono-Regular'), url(6NUO8FuJNQ2MbkrZ5-J8lKFrp7pRef2u.ttf) format('truetype');
-}
-@font-face {
-  font-family: 'Noto Serif';
-  font-style: italic;
-  font-weight: 400;
-  src: local('Noto Serif Italic'), local('NotoSerif-Italic'), url(ga6Kaw1J5X9T9RW6j9bNfFImajC-.ttf) format('truetype');
-}
-@font-face {
-  font-family: 'Noto Serif';
-  font-style: italic;
-  font-weight: 700;
-  src: local('Noto Serif Bold Italic'), local('NotoSerif-BoldItalic'), url(ga6Vaw1J5X9T9RW6j9bNfFIu0RWuc-VJ.ttf) format('truetype');
-}
-@font-face {
-  font-family: 'Noto Serif';
-  font-style: normal;
-  font-weight: 400;
-  src: local('Noto Serif'), local('NotoSerif'), url(ga6Iaw1J5X9T9RW6j9bNfFcWbQ.ttf) format('truetype');
-}
-@font-face {
-  font-family: 'Noto Serif';
-  font-style: normal;
-  font-weight: 700;
-  src: local('Noto Serif Bold'), local('NotoSerif-Bold'), url(ga6Law1J5X9T9RW6j9bNdOwzfReedA.ttf) format('truetype');
-}
-@font-face {
-  font-family: 'Open Sans';
-  font-style: italic;
-  font-weight: 300;
-  src: local('Open Sans Light Italic'), local('OpenSans-LightItalic'), url(memnYaGs126MiZpBA-UFUKWyV9hrIqY.ttf) format('truetype');
-}
-@font-face {
-  font-family: 'Open Sans';
-  font-style: italic;
-  font-weight: 400;
-  src: local('Open Sans Italic'), local('OpenSans-Italic'), url(mem6YaGs126MiZpBA-UFUK0Zdcg.ttf) format('truetype');
-}
-@font-face {
-  font-family: 'Open Sans';
-  font-style: italic;
-  font-weight: 600;
-  src: local('Open Sans SemiBold Italic'), local('OpenSans-SemiBoldItalic'), url(memnYaGs126MiZpBA-UFUKXGUdhrIqY.ttf) format('truetype');
-}
-@font-face {
-  font-family: 'Open Sans';
-  font-style: normal;
-  font-weight: 300;
-  src: local('Open Sans Light'), local('OpenSans-Light'), url(mem5YaGs126MiZpBA-UN_r8OUuhs.ttf) format('truetype');
-}
-@font-face {
-  font-family: 'Open Sans';
-  font-style: normal;
-  font-weight: 400;
-  src: local('Open Sans Regular'), local('OpenSans-Regular'), url(mem8YaGs126MiZpBA-UFVZ0e.ttf) format('truetype');
-}
-@font-face {
-  font-family: 'Open Sans';
-  font-style: normal;
-  font-weight: 600;
-  src: local('Open Sans SemiBold'), local('OpenSans-SemiBold'), url(mem5YaGs126MiZpBA-UNirkOUuhs.ttf) format('truetype');
-}