* Add 4 books

* Alphabetic order and 2 more books

* Update free-programming-books-ru.md

* Update free-podcasts-screencasts-ru.md

* Update free-podcasts-screencasts-ru.md

* Update free-programming-books-ru.md

* Update free-programming-books-ru.md

* add required space, add clojure to index

* add pdf indication

* remove trailing slashed, fix "alphabetical" order

The thing that was confusing us is that the С was capitalized, so its code point was before lower case п, but the sorting is case insensitive. Oh my. This is why we need a robot that fixes these things.

* trailing slash