fix: dont throw error when session was already stopped

.gitignore

@@ -4,3 +4,5 @@ doc/tags
 debug
 .repro
 foo.*
+*.log
+data

README.md

@@ -9,7 +9,7 @@
 
 ## ⚡️ Requirements
 
-- Neovim >= 0.5.0
+- Neovim >= 0.7.2
 
 ## 📦 Installation
 

lua/persistence/init.lua

@@ -27,19 +27,16 @@ function M.setup(opts)
 end
 
 function M.start()
-  vim.cmd([[
+  vim.api.nvim_create_autocmd("VimLeavePre", {
-    augroup Persistence
+    group = vim.api.nvim_create_augroup("persistence", { clear = true }),
-      autocmd!
+    callback = function()
-      autocmd VimLeavePre * lua require("persistence").save()
+      M.save()
-    augroup end
+    end,
-  ]])
+  })
 end
 
 function M.stop()
-  vim.cmd([[
+  pcall(vim.api.nvim_del_augroup_by_name, "persistence")
-  autocmd! Persistence
-  augroup! Persistence
-  ]])
 end
 
 function M.save()