feat: gh-actions-language-server #3551

lua/lspconfig/configs/gh_actions_ls.lua

@@ -0,0 +1,40 @@
+local util = require 'lspconfig.util'
+
+return {
+  default_config = {
+    cmd = { 'gh-actions-language-server', '--stdio' },
+    filetypes = { 'yaml.github' },
+    root_dir = util.root_pattern('.github'),
+    single_file_support = true,
+    capabilities = {
+      workspace = {
+        didChangeWorkspaceFolders = {
+          dynamicRegistration = true,
+        },
+      },
+    },
+  },
+  docs = {
+    description = [[
+https://github.com/lttb/gh-actions-language-server
+
+Language server for GitHub Actions.
+
+The server is registered for the special `yaml.github` filetype. You need to configure this filetype pattern for GitHub workflow files.
+
+```lua
+vim.filetype.add({
+  pattern = {
+    ['.*/%.github[%w/]+workflows[%w/]+.*%.ya?ml'] = 'yaml.github',
+  },
+})
+```
+
+`gh-actions-language-server` can be installed via `npm`:
+
+```sh
+npm install -g gh-actions-language-server
+```
+]],
+  },
+}