Add more punctuation marks to splitter

Closes GH-7.

This commit adds comma (`,`), colon (`:`), semicolon (`;`), exclamation mark
(`!`), question mark (`?`), and parens (`(` and `)`) to the list of stops.

index.js

@@ -31,13 +31,17 @@ export function apStyleTitleCase(value, options) {
 
   const stop = configuration.stopwords || defaults
   const keep = configuration.keepSpaces
-  const splitter = /(\s+|[-‑–—])/
+  const splitter = /(\s+|[-‑–—,:;!?()])/
 
   return value
     .split(splitter)
     .map((word, index, all) => {
-      if (/\s+/.test(word)) return keep ? word : ' '
-      if (splitter.test(word)) return word
+      // The splitter:
+      if (index % 2) {
+        if (/\s+/.test(word)) return keep ? word : ' '
+        return word
+      }
+
       const lower = word.toLowerCase()
 
       if (index !== 0 && index !== all.length - 1 && stop.includes(lower)) {

test.js

@@ -43,7 +43,8 @@ test('ap-style-title-case', function () {
     [
       'Observations of isolated pulsars and disk-fed X-ray binaries.',
       'Observations of Isolated Pulsars and Disk-Fed X-Ray Binaries.'
-    ]
+    ],
+    ['Shakspeare; Or, the Poet', 'Shakspeare; or, the Poet']
   ]
 
   for (const pattern of patterns) {