suport chapterTitle

Author: azu

src/plugin.js

@@ -56,8 +56,10 @@ window.require(["gitbook"], function(gitbook) {
             var apiURL = getAPIURL(config, pathname);
             var resourceURL = getResourceURL(config, pathname, "master");
             var editURL = getEditURL(config, gitbook.state.filepath, "master");
+            var chapterTitle = gitbook.state.chapterTitle;
             getContentAsync(apiURL).then(function(markdown) {
                 var bug = new BugReporter(getIssueURL(config));
+                bug.setTitle(chapterTitle);
                 var selectedText = bug.getSelectedText().trim();
                 let body = 'URL : ' + resourceURL + "\n\n";
                 if (selectedText && selectedText.length > 0) {