Web search engine compatibility

[astyled]

I have noticed this a few times when I was searching for some userstyles, and it was recently pointed in #287 in a comment (at the very bottom), that search engines are not able to correctly index USw. This makes it appear very rarely in the results and always broken.

[astyled]

[astyled]

Some research:

• all websites i tried duplicate content in <meta name="description"> and <meta property="og:description">;
• i think we should only keep USw description (A new free and open-source, community-driven, modern alternative to userstyles.org.) for service pages like home, explore, and have something else for UGC pages like profiles and styles;
• we should de-markdown descriptions of profiles for the meta tags;
• we need a description placeholder for cases where there's no or not enough content in profile biography. like Browse {username}'s userstyles at userstyles.world — a new free and open-source, community-driven userstyles repository;
• something similar may be good for style descriptions. {short description}. Get this userstyle for {category} on userstyles.world.