Check file time after entering a buf

lua/autocommands.lua

@@ -32,6 +32,9 @@ local autocmds = {
       {'BufRead,BufNewFile', 'Jenkinsfile*', 'set filetype=groovy'};
       {'BufRead,BufNewFile', '*.manifest', 'set filetype=xml'};
       {'BufRead,BufNewFile', 'SConstruct,SConscript', 'set filetype=python'};
+    };
+    file_changed = {
+      {'BufEnter,FocusGained', '*', 'checktime'};
     }
 }