Don't re render on hash anchors from markdown wrapper

[f0rr0]

This should be set by default. Markdown headings usually have anchor hashes. The component gets re-rendered if the hash link is clicked.

[KyleAMathews]

Oh? Didn't realize this. How do you stop the rerender? Some react-router config?

[KyleAMathews]

related: #386

[emilyaviva]

What about https://github.com/adjohnson916/anchorate? (I see @ivanoats already pointed to this in the #386)

[f0rr0]

@KyleAMathews a naive way could be to intercept links with #something in componentDidMount and then

document.querySelector(`#${something}`).scrollIntoView();

[f0rr0]

that could be followed up with:

window.history.pushState(null, null, `#${something}`);

However, the back button does not seem to work as expected

[f0rr0]

I think this issue was being faced by Phenomic as well taion/react-router-scroll#37

The behavior I am seeing is the same as mentioned in the issue above

[KyleAMathews]

On not re-rendering, just was investigating this — easiest solution is to add a shouldComponentUpdate on routes and don't render on hash changes. This is possibly something Gatsby could add automatically as we generate the routes and could wrap them with a sCU like this.