Update sources links in the docs, or remove them entirely

[vpavkin]

As noted here, all pages should be updated.

There's another problem with those links: they are not shown anywhere. Template markup has useful links section, but it's hidden by this css line.

So the question is: Do we need those links in the first place?

[vpavkin]

How about show useful links section with updated styles? E.g. like this:

Should look ok on mobiles too:

If it's ok, I'll make a pr :)

[adelbertc]

👍