Add JetBrains Mono font for code/pre

package.json

@@ -3,7 +3,7 @@
   "version": "4.1.0",
   "private": true,
   "hexo": {
-    "version": "4.2.0"
+    "version": "4.2.1"
   },
   "dependencies": {
     "hexo": "^4.2.0",
@@ -17,4 +17,4 @@
     "hexo-renderer-stylus": "^1.1.0",
     "hexo-server": "^1.0.0"
   }
-}
+}

themes/bit-badger/source/style.css

@@ -1,4 +1,13 @@
 @import url('https://fonts.googleapis.com/css?family=Oswald|Raleway');
+@font-face {
+  font-family: 'JetBrains Mono';
+  src: url('https://raw.githubusercontent.com/JetBrains/JetBrainsMono/master/web/eot/JetBrainsMono-Regular.eot') format('embedded-opentype'),
+       url('https://raw.githubusercontent.com/JetBrains/JetBrainsMono/master/web/woff2/JetBrainsMono-Regular.woff2') format('woff2'),
+       url('https://raw.githubusercontent.com/JetBrains/JetBrainsMono/master/web/woff/JetBrainsMono-Regular.woff') format('woff'),
+       url('https://raw.githubusercontent.com/JetBrains/JetBrainsMono/master/ttf/JetBrainsMono-Regular.ttf') format('truetype');
+  font-weight: normal;
+  font-style: normal;
+}
 html {
   background-color: lightgray;
 }
@@ -48,7 +57,8 @@ p {
   margin: 1rem 0;
 }
 code, pre {
-  font-family: "SFMono-Regular",Consolas,"Liberation Mono",Menlo,Courier,monospace;
+  font-family: "JetBrains Mono","SFMono-Regular",Consolas,"Liberation Mono",Menlo,Courier,monospace;
+  font-size: 1rem;
 }
 code {
   background-color: rgba(0, 0, 0, .1);
@@ -56,8 +66,6 @@ code {
 }
 #content {
   margin: 0 1rem;
-}
-.content {
   font-size: 1.1rem;
 }
 .auto {