Replace references to pylsp with pyls (#1378)

The palantir pyls repository is no longer maintained, the documentation
should not lead user down the path of configuring this dead end project.
pylps is the actively maintained sucessor project forked from pyls.

autoload/lsp.vim

@@ -14,7 +14,7 @@ let s:notification_callbacks = [] " { name, callback }
 "        "bingo": [ "first-line", "next-line", ... ]
 "      },
 "      2: {
-"        "pyls": [ "first-line", "next-line", ... ]
+"        "pylsp": [ "first-line", "next-line", ... ]
 "      }
 "    }
 let s:file_content = {}