feat: add link() helper

* Based on link_to() helper, without unneeded attribute and option
* https://hexo.io/docs/helpers#link-to

themes/typing/layout/_partial/footer.ejs

@@ -10,6 +10,6 @@
   <hr>
 <% } %>
 <div id="copyright" class="copyright">
-  &copy; 2018-<%= date(new Date(), 'YYYY') %> <%= config.author %>. <%- link_to('https://gitlab.com/curben/blog', 'Powered by ') %> <%- link_to('https://hexo.io/', 'Hexo') %> with <%- link_to('https://github.com/geekplux/hexo-theme-typing', 'Typing') %> theme. <br/>Content is available under <%- link_to('https://creativecommons.org/licenses/by-sa/4.0/', 'CC-BY-SA 4.0') %>, unless indicated otherwise. <br/><%- link_to('/disclaimer/', 'Disclaimer') %>
+  &copy; 2018-<%= date(new Date(), 'YYYY') %> <%= config.author %>. <%- link('https://gitlab.com/curben/blog', 'Powered by ') %> <%- link('https://hexo.io/', 'Hexo') %> with <%- link('https://github.com/geekplux/hexo-theme-typing', 'Typing') %> theme. <br/>Content is available under <%- link('https://creativecommons.org/licenses/by-sa/4.0/', 'CC-BY-SA 4.0') %>, unless indicated otherwise. <br/><%- link('/disclaimer/', 'Disclaimer') %>
 </div>
 </footer>

themes/typing/scripts/link.js

@@ -0,0 +1,25 @@
+/*
+* Modified from the hexo version,
+* https://github.com/hexojs/hexo/blob/master/lib/plugins/helper/link_to.js
+* to remove title attribute and 'external' option
+*/
+
+'use strict'
+
+const { htmlTag } = require('hexo-util')
+
+function linkHelper(path, text) {
+  if (!text) text = path.replace(/^https?:\/\/|\/$/g, '')
+
+  const attrs = Object.assign({
+    href: this.url_for(path)
+  })
+
+  if (attrs.class && Array.isArray(attrs.class)) {
+    attrs.class = attrs.class.join(' ')
+  }
+
+  return htmlTag('a', attrs, text)
+}
+
+hexo.extend.helper.register('link', linkHelper)