feat(lsp): Set up vtsls, vue_ls, install miscellaneous plugins

after/plugin/null_ls.lua

@@ -0,0 +1,12 @@
+local null_ls = require("null-ls")
+
+local options = {
+	sources = {
+		null_ls.builtins.diagnostics.phpcs.with({
+			command = "phpcs",
+			args = { "--report=json", "--stdin-path=$FILENAME", "-" },
+		}),
+	},
+}
+
+null_ls.setup(options)