Rename function firstBig => capitalize (#140)

Author: yuler

lib/help.js

@@ -2,7 +2,7 @@
 
 module.exports = function() {
   const name = this.config.name || this.binary.replace('-', ' ')
-  const firstBig = word => word.charAt(0).toUpperCase() + word.substr(1)
+  const capitalize = word => word.charAt(0).toUpperCase() + word.substr(1)
 
   const parts = []
 
@@ -37,7 +37,7 @@ module.exports = function() {
       continue
     }
 
-    parts.push(['', firstBig(group) + ':', ''])
+    parts.push(['', capitalize(group) + ':', ''])
 
     if (group === 'examples') {
       parts.push(this.generateExamples())