Restructure Darwin configuration

So far, this is just based on mightymac. The other devices will be
updated soon.

modules/home-manager/files/nvim/lua/plugins/lsp-config.lua

@@ -1,65 +0,0 @@
-return {
-  {
-    "williamboman/mason.nvim",
-    config = true,
-  },
-  {
-    "williamboman/mason-lspconfig.nvim",
-    config = function()
-      require("mason-lspconfig").setup({
-        ensure_installed = {
-          "lemminx", -- xml
-          "lua_ls", -- lua
-          "nil_ls", -- nix
-          "puppet", -- puppet
-          "ruff", -- python
-        },
-      })
-    end,
-  },
-  {
-    "neovim/nvim-lspconfig",
-    config = function()
-      local on_attach = function(_, _)
-        vim.keymap.set("n", "<leader>rn", vim.lsp.buf.rename, {})
-        vim.keymap.set("n", "<leader>ca", vim.lsp.buf.code_action, {})
-
-        vim.keymap.set("n", "gd", vim.lsp.buf.definition, {})
-        vim.keymap.set("n", "gi", vim.lsp.buf.implementation, {})
-        vim.keymap.set("n", "gr", require("telescope.builtin").lsp_references, {})
-        vim.keymap.set("n", "K", vim.lsp.buf.hover, {})
-      end
-
-      local lspconfig = require("lspconfig")
-      local capabilities = require("cmp_nvim_lsp").default_capabilities()
-
-      lspconfig.lemminx.setup({
-        capabilities = capabilities,
-        on_attach = on_attach,
-      })
-
-      lspconfig.lua_ls.setup({
-        capabilities = capabilities,
-        on_attach = on_attach,
-        settings = { Lua = { diagnostics = { globals = { "vim" } } } },
-      })
-
-      lspconfig.nil_ls.setup({
-        capabilities = capabilities,
-        on_attach = on_attach,
-      })
-
-      local puppet_languageserver = vim.fn.expand(
-        "$HOME/.local/share/nvim/mason/packages/puppet-editor-services/libexec/puppet-languageserver"
-      )
-
-      lspconfig.puppet.setup({
-        capabilities = capabilities,
-        on_attach = on_attach,
-        cmd = { puppet_languageserver, "--feature-flags=puppetstrings" },
-        settings = { puppet = { editorServices = { formatOnType = { enable = true } } } },
-      })
-      lspconfig.ruff.setup({ on_attach = on_attach })
-    end,
-  },
-}