fix sidebar active element highlighting

[praveenweb]

The highlighting of active element on the left sidebar doesn't seem to work. It's probably an issue with URL matching that ends without slashes.

[i001962]

#22 causes gatsby build to fail.

Building static HTML failed for path "/"

See our docs page for more info on this error: https://gatsby.dev/debug-html


   5 | import Link from "../link";
   6 | 
>  7 | const TreeNode = ({className = '', setCollapsed, collapsed, url, title, items, location = document.location, ...rest}) => {
     |                                                                                           ^
   8 |   const isCollapsed = collapsed[url];
   9 |   const collapse = () => {
  10 |     setCollapsed(url);


  WebpackError: ReferenceError: document is not defined

[praveenweb]

@i001962 - Thanks for pointing out. Builds failed obviously because document is available only on the client and not during build phase. Fixed it via 0c4d894