User.js: Recommended addons: Add Decentraleyes

[nodiscc]

Ref https://github.com/pyllyukko/user.js/issues/145#issuecomment-220999839

[Gitoffthelawn]

@CHEF-KOCH In another issue (https://github.com/pyllyukko/user.js/issues/145#issuecomment-220848287), you wondered if I had any feedback on Decentraleyes (https://github.com/Synzvato/decentraleyes). Sorry it's taken me this long to reply. Been very busy.

In my experience testing Decentraleyes, I found it to work as expected without any issues. I experienced no reliability issues at all. I think it is a good tool to recommend.

In it's current implementation, the developer has made a trade-off between extension size and catching more calls to CDN's. IOW, instead of catching almost all calls and having the extension be 1-2GB, he has chosen to have it catch the _most common calls_ and be much smaller in size. It's a reasonable approach.

There are some ongoing discussions regarding allowing the extension to be extensible to handle even more CDN calls while simultaneously decreasing the extension's size. I proposed one possible design here: https://github.com/Synzvato/decentraleyes/issues/91#issuecomment-221850897

[pyllyukko]

I'll try this out before adding it to the README. Seems promising.