Update the contribution guidelines
[#912] Improve a bit the robustness of the cider-restart command
Remove redundant url-encode-url invocation

The Javadoc URLs are now properly encoded in the middleware.
See https://github.com/clojure-emacs/cider-nrepl/commit/706e916ea91707b8f87f08dab2f025c756b14ad2
[Fix #885] Ensure text property keys are symbols.

Maps received via nREPL have string keys.  The Emacs Lisp text property
functions expect all property keys to be symbols.  Thus we must first intern any
non-symbol property keys prior to applying them as text properties.
Merge pull request #918 from llasram/intern-keys

Ensure text property keys are symbols.
[Fix #495] Add some ClojureScript usage documentation.
Tidy table of contents in README.md