Update term_browser and entry replacements in ohd.yml

[wdduncan]

Changed redirect to OLS.

[wdduncan]

Thanks @jamesaoverton
What was the issue? Wondering what I did wrong.

[jamesaoverton]

The /about/ entry needed two changes:

1. It's better to use the /terms/ endpoint in OLS, because you also want to handle properties and not just /classes/. OLS will redirect to classes or properties as appropriate.
2. The /terms/ endpoint also needs the first part of the IRI.

See my commit a311fa5.

[wdduncan]

Thanks!