feat(nvim): rustfmt config

vim/lua/formatter_config.lua

@@ -22,6 +22,14 @@ local goimports = function()
 	}
 end
 
+local rustfmt = function()
+	return {
+		exe = "rustfmt",
+		args = { "--edition", "2021" },
+		stdin = true,
+	}
+end
+
 require("formatter").setup({
 	log_level = vim.log.levels.INFO,
 	filetype = {
@@ -29,6 +37,7 @@ require("formatter").setup({
 		typescript = { prettier },
 		typescriptreact = { prettier },
 		go = { goimports },
+		rust = { rustfmt },
 
 		-- https://github.com/JohnnyMorganz/StyLua
 		-- cargo install stylua --features lua54
@@ -43,7 +52,7 @@ vim.api.nvim_exec2(
 	[[
 augroup FormatAutogroup
   autocmd!
-  autocmd BufWritePost *.js,*.ts,*.tsx,*.go,*.lua silent FormatWrite
+  autocmd BufWritePost *.js,*.ts,*.tsx,*.go,*.lua,*.rs silent FormatWrite
 augroup END
 ]],
 	{ output = true }