Docs update

docs/script/inner-link.js

@@ -0,0 +1,32 @@
+// inner link(#foo) can not correctly scroll, because page has fixed header,
+// so, I manually scroll.
+(function(){
+  var matched = location.hash.match(/errorLines=([\d,]+)/);
+  if (matched) return;
+
+  function adjust() {
+    window.scrollBy(0, -55);
+    var el = document.querySelector('.inner-link-active');
+    if (el) el.classList.remove('inner-link-active');
+
+    // ``[ ] . ' " @`` are not valid in DOM id. so must escape these.
+    var id = location.hash.replace(/([\[\].'"@$])/g, '\\$1');
+    var el = document.querySelector(id);
+    if (el) el.classList.add('inner-link-active');
+  }
+
+  window.addEventListener('hashchange', adjust);
+
+  if (location.hash) {
+    setTimeout(adjust, 0);
+  }
+})();
+
+(function(){
+  var els = document.querySelectorAll('[href^="#"]');
+  var href = location.href.replace(/#.*$/, ''); // remove existed hash
+  for (var i = 0; i < els.length; i++) {
+    var el = els[i];
+    el.href = href + el.getAttribute('href'); // because el.href is absolute path
+  }
+})();