Move lsp config to local file structure

.config/nvim/lsp/sourcekit.lua

@@ -0,0 +1,40 @@
+---@brief
+---
+--- https://github.com/swiftlang/sourcekit-lsp
+---
+--- Language server for Swift and C/C++/Objective-C.
+
+local util = require 'lspconfig.util'
+
+---@type vim.lsp.Config
+return {
+  cmd = { 'sourcekit-lsp' },
+  filetypes = { 'swift', 'objc', 'objcpp', 'c', 'cpp' },
+  root_dir = function(bufnr, on_dir)
+    local filename = vim.api.nvim_buf_get_name(bufnr)
+    on_dir(
+      util.root_pattern('buildServer.json', '.bsp')(filename)
+        or util.root_pattern('*.xcodeproj', '*.xcworkspace')(filename)
+        -- better to keep it at the end, because some modularized apps contain multiple Package.swift files
+        or util.root_pattern('compile_commands.json', 'Package.swift')(filename)
+        or vim.fs.dirname(vim.fs.find('.git', { path = filename, upward = true })[1])
+    )
+  end,
+  get_language_id = function(_, ftype)
+    local t = { objc = 'objective-c', objcpp = 'objective-cpp' }
+    return t[ftype] or ftype
+  end,
+  capabilities = {
+    workspace = {
+      didChangeWatchedFiles = {
+        dynamicRegistration = true,
+      },
+    },
+    textDocument = {
+      diagnostic = {
+        dynamicRegistration = true,
+        relatedDocumentSupport = true,
+      },
+    },
+  },
+}