use either 'e' or 'i' for empty buffer

People seem to like both, so I made both of them defaults.
(I changed [i] back to [e] nevertheless.)

plugin/startify.vim

@@ -47,7 +47,7 @@ function! s:insane_in_the_membrane() abort
   let cnt = 0
 
   if special
-    call append('$', '   [i]  <empty buffer>')
+    call append('$', '   [e]  <empty buffer>')
   endif
 
   if get(g:, 'startify_show_files', 1) && !empty(v:oldfiles)
@@ -99,6 +99,7 @@ function! s:insane_in_the_membrane() abort
 
   setlocal nomodifiable nomodified
 
+  nnoremap <buffer><silent> e :enew<cr>
   nnoremap <buffer><silent> i :enew<cr>
   nnoremap <buffer> <cr> :normal <c-r><c-w><cr>
   nnoremap <buffer> <2-LeftMouse> :execute 'normal '. matchstr(getline('.'), '\w\+')<cr>