feat: add lwc-language-server support

lua/lspconfig/server_configurations/lwc_ls.lua

@@ -0,0 +1,38 @@
+local util = require 'lspconfig.util'
+
+return {
+  default_config = {
+    cmd = { 'lwc-language-server', '--stdio' }
+    filetypes = { 'javascript', 'html' },
+    root_dir = util.root_pattern 'sfdx-project.json',
+    init_options = {
+      embeddedLanguages = {
+        javascript = true,
+      },
+    },
+  },
+  docs = {
+    description = [[
+https://github.com/forcedotcom/lightning-language-server/
+
+Language server for Lightning Web Components.
+
+For manual installation, utilize the official 
+[NPM package](https://www.npmjs.com/package/@salesforce/lwc-language-server). 
+Then, configure `cmd` to run the Node script at the unpacked location:
+
+```lua
+require'lspconfig'.lwc_ls.setup {
+  cmd = {
+    'node',
+    '/path/to/node_modules/@salesforce/lwc-language-server/bin/lwc-language-server.js',
+    '--stdio'
+  }
+}
+```
+]],
+    default_config = {
+      root_dir = [[root_pattern('sfdx-project.json')]],
+    },
+  },
+}