[index] Show bridge options when loading with URL fragment

Loading the page with an URL fragement (#bridge-*) should result in
the bridge showing all parameters by default. Unfortunately this is
not possible using PHP, which is why a new JavaScript function is
needed (select.js)

That way, when returning from a bridge ('back to rss-bridge') will
keep the selected bridge active (only works for HTML format).

static/select.js

@@ -0,0 +1,10 @@
+function select(){
+	var fragment = window.location.hash.substr(1);
+	var bridge = document.getElementById(fragment);
+
+	if(bridge !== null) {
+		bridge.getElementsByClassName('showmore-box')[0].checked = true;
+	}
+}
+
+document.addEventListener('DOMContentLoaded', select);