Add a FAQ about not jumping to first result

References #59. Thanks @ejoubaud for the succinct abbreviation
suggestion that I wish we documented a long time ago.

README.md

@@ -122,6 +122,19 @@ nice code clean-up (which ack.vim is now hopefully getting), and ack.vim picked
 up a few features that haven't made their way to ag.vim, like `:AckWindow`,
 optional background search execution with [vim-dispatch], and auto-previewing.
 
+#### I don't want to jump to the first result automatically. ####
+
+Use `:Ack!`, with bang. If you want this behavior most of the time, you might
+like an abbreviation or mapping in your personal config, something like these:
+
+```vim
+cnoreabbrev Ack Ack!
+nnoremap <Leader>a :Ack!<Space>
+```
+
+Most of the `:[L]Ack*` commands support this. Note that this behavior follows
+the convention of Vim's built-in `:grep` and `:make` commands.
+
 [The Silver Searcher]: https://github.com/ggreer/the_silver_searcher
 [sadface]: https://github.com/mileszs/ack.vim/commit/d97090fb502d40229e6976dfec0e06636ba227d5#commitcomment-5771145
 

doc/ack.txt

@@ -275,7 +275,19 @@ If you're using this plugin with ag, The Silver Searcher, bear in mind that:
 ==============================================================================
 ISSUES AND FAQ                                            *ack-issues-and-faq*
 
-I use NERDTree and opening ack.vim results in a vertical split displaces it.~
+I don't want to jump to the first result automatically.~
+
+    Use `:Ack!`, with bang. If you want this behavior most of the time, you
+    might like an abbreviation or mapping in your personal config, something
+    like these:
+>
+        cnoreabbrev Ack Ack!
+        nnoremap <Leader>a :Ack!<Space>
+<
+    Most of the `:[L]Ack*` commands support this. Note that this behavior
+    follows the convention of Vim's built-in |:grep| and |:make| commands.
+
+I use NERDTree and opening ack.vim results in a vertical split displacing it.~
 
     You are probably using NERDTree with its default alignment at the left
     side of the window. Set these custom mappings in your vimrc to work around