Search results should strip formatting e.g. h1 tag
Example search: https://forum.nim-lang.org/search?q=postgres

<img width="1044" alt="CleanShot 2021-01-18 at 19 54 09@2x" src="https://user-images.githubusercontent.com/81271/104982058-132cd000-59c7-11eb-9465-f486e08d74c2.png">

<img width="387" alt="CleanShot 2021-01-18 at 19 55 19@2x" src="https://user-images.githubusercontent.com/81271/104982075-1aec7480-59c7-11eb-8751-84cf96219fcf.png">
