feat: add cue language server (#3529)

* feat: cue language server


---------

Co-authored-by: glepnir <glephunter@gmail.com>

lua/lspconfig/configs/cue.lua

@@ -0,0 +1,19 @@
+local util = require 'lspconfig.util'
+
+return {
+  default_config = {
+    cmd = { 'cue', 'lsp' },
+    filetypes = { 'cue' },
+    root_dir = function(fname)
+      return util.root_pattern(unpack({ 'cue.mod', '.git' }))(fname)
+    end,
+    single_file_support = true,
+  },
+  docs = {
+    description = [[
+https://github.com/cue-lang/cue
+
+CUE makes it easy to validate data, write schemas, and ensure configurations align with policies.
+]],
+  },
+}