Fix 'Donate' link in FAQ page

docs/_i18n/en/faq/faq.md

@@ -56,4 +56,4 @@ onClickRow: function (row, $element) {
 
 All your ideas and feedback are very appreciated! Please feel free to open issues on GitHub or send me email.
 
-I'm also grateful for your donations: <a href="donate">{% t pages.donate.title %}</a>
+I'm also grateful for your donations: <a href="/donate">{% t pages.donate.title %}</a>

docs/_i18n/es/faq/faq.md

@@ -56,4 +56,4 @@ onClickRow: function (row, $element) {
 
 All your ideas and feedback are very appreciated! Please feel free to open issues on GitHub or send me email.
 
-I'm also grateful for your donations: <a href="donate">{% t pages.donate.title %}</a>
+I'm also grateful for your donations: <a href="/donate">{% t pages.donate.title %}</a>

docs/_i18n/zh-cn/faq/faq.md

@@ -54,4 +54,4 @@ onClickRow: function (row, $element) {
 
 非常感谢你的想法和建议，你可以到 GitHub 上提 issue 或者发邮件给我。
 
-当然，假如你也可以 <a href="donate">{% t pages.donate.title %}</a> 我们的项目。
+当然，假如你也可以 <a href="/donate">{% t pages.donate.title %}</a> 我们的项目。