Close joaotavora#905: Add out-of-box support for PureScript LSP server

* eglot.el (eglot-server-programs): Support purescript lsp.
* README.md: Update.
* NEWS.md: Update.

Copyright-paperwork-exempt: Yes

NEWS.md

@@ -46,6 +46,7 @@ available.  The special support code for RLS has been removed.
 - clojure-lsp ([#813][github#813])
 - racket-langserver ([#694][github#694])
 - futhark lsp ([#922](github#922))
+- purescript-language-server ([#905](github#905))
 
 # 1.8 (12/1/2022)
 
@@ -375,4 +376,5 @@ and now said bunch of references-->
 [github#893]: https://github.com/joaotavora/eglot/issues/893
 [github#899]: https://github.com/joaotavora/eglot/issues/899
 [github#901]: https://github.com/joaotavora/eglot/issues/901
+[github#905]: https://github.com/joaotavora/eglot/issues/905
 [github#922]: https://github.com/joaotavora/eglot/issues/922

README.md

@@ -65,6 +65,7 @@ find-library` can help you tell if that happened.
 * Nix's [rnix-lsp][rnix-lsp]
 * Ocaml's [ocaml-lsp][ocaml-lsp]
 * PHP's [php-language-server][php-language-server]
+* PureScript's [purescript-language-server][purescript-language-server]
 * Python's [pylsp][pylsp], [pyls][pyls] or [pyright][pyright]
 * R's [languageserver][r-languageserver]
 * Racket's [racket-langserver][racket-langserver]
@@ -522,6 +523,7 @@ for the request form, and we'll send it to you.
 [rnix-lsp]: https://github.com/nix-community/rnix-lsp
 [ocaml-lsp]: https://github.com/ocaml/ocaml-lsp/
 [php-language-server]: https://github.com/felixfbecker/php-language-server
+[purescript-language-server]: https://github.com/nwolverson/purescript-language-server
 [pyls]: https://github.com/palantir/python-language-server
 [pylsp]: https://github.com/python-lsp/python-lsp-server
 [pyright]: https://github.com/microsoft/pyright

eglot.el

@@ -195,7 +195,8 @@ language-server/bin/php-language-server.php"))
                                 (json-mode . ,(eglot-alternatives '(("vscode-json-language-server" "--stdio") ("json-languageserver" "--stdio"))))
                                 (dockerfile-mode . ("docker-langserver" "--stdio"))
                                 (clojure-mode . ("clojure-lsp"))
-                                (csharp-mode . ("omnisharp" "-lsp")))
+                                (csharp-mode . ("omnisharp" "-lsp"))
+                                (purescript-mode . ("purescript-language-server" "--stdio")))
   "How the command `eglot' guesses the server to start.
 An association list of (MAJOR-MODE . CONTACT) pairs.  MAJOR-MODE
 identifies the buffers that are to be managed by a specific