Make URLs clickable

**Is your feature request related to a problem? Please describe.**
I was recently viewing a post in Phanpy, which contains a URL. I wanted to click on the URL, when I realized that it's just plain text, not a clickable link.

**Describe the solution you'd like**
Make URLs clickable

**Describe alternatives you've considered**
Using the [Linkify Plus Plus](https://greasyfork.org/en/scripts/4255-linkify-plus-plus) userscript

**Additional context**

With Linkify Plus Plus:

The issue does not name a file or test. Start by locating the post-rendering entry point in the web client and inspect how post text is displayed; done means URLs in posts are rendered as clickable links without breaking ordinary text.

Written by the indexing model from the issue text.