Add kotlin-language-server (joaotavora#70)

https://github.com/fwcd/KotlinLanguageServer

copyright-paperwork-exempt: yes

* README.md (Installation and Usage): declare Kotlin support.

README.md

@@ -32,6 +32,7 @@ for the language of your choice. Otherwise, it prompts you to enter one:
 * PHP's [php-language-server][php-language-server]
 * C/C++'s [cquery][cquery]
 * Haskell's [IDE engine][haskell-ide-engine]
+* Kotlin's [kotlin-language-server][kotlin-language-server]
 
 I'll add to this list as I test more servers. In the meantime you can
 customize `eglot-server-programs`:
@@ -286,4 +287,5 @@ Under the hood:
 [solargraph]: https://github.com/castwide/solargraph
 [windows-subprocess-hang]: https://www.gnu.org/software/emacs/manual/html_node/efaq-w32/Subprocess-hang.html
 [haskell-ide-engine]: https://github.com/haskell/haskell-ide-engine
+[kotlin-language-server]: https://github.com/fwcd/KotlinLanguageServer
 

eglot.el

@@ -90,7 +90,8 @@
                                     :autoport))
                                 (php-mode . ("php" "vendor/felixfbecker/\
 language-server/bin/php-language-server.php"))
-                                (haskell-mode . ("hie-wrapper")))
+                                (haskell-mode . ("hie-wrapper"))
+                                (kotlin-mode . ("kotlin-language-server")))
   "How the command `eglot' guesses the server to start.
 An association list of (MAJOR-MODE . CONTACT) pairs.  MAJOR-MODE
 is a mode symbol, or a list of mode symbols.  The associated