Update br tags

[adrianeboyd]

Description

I think the intention in displacy was <br/>, but maybe now <br> would be better (says the w3c markup validator anyway)?

Types of change

Bug fix?

Checklist

• I confirm that I have the right to submit this contribution under the project's MIT license.
• I ran the tests, and all new and existing tests passed.
• My changes don't require a change to the documentation, or if they do, I've added all required information.

[rmitsch]

Does this fix a bug? I just wouldn't want to assume the closing tag is an opening tag. <br> should be sufficient now AFAIK, yes (not an expert though).

[adrianeboyd]

I think all browsers probably render <br>, </br>, and <br/> the same so it's not exactly a bug? It's been like this for ages. I'd noticed a few times in the past when inspecting the rendering but never worried about it beyond that. But I don't think that </br> has ever been an actual valid tag?

[rmitsch]

Ah right, it's just line break.

[svlandeg]

If the w3c markup validator suggests <br> I would yet change it into that, but I suspect that it won't make a practical difference either way.