g:zig_fmt_autoswitch: cfg location list autoswitch

```vim
" don't automatically switch to location list if zig fmt encounters errors
let g:zig_fmt_autoswitch = 0
```

Author: atweiden

README.md

@@ -37,6 +37,14 @@ This plugin enables automatic code formatting on save by default using
 let g:zig_fmt_autosave = 0
 ```
 
+If `zig fmt` encounters a code formatting error, this plugin populates
+the location list with relevant errors. To disable automatically switching
+to the location list, use this configuration in vimrc:
+
+```
+let g:zig_fmt_autoswitch = 0
+```
+
 The default compiler which gets used by `:make` (`:help :compiler` for details)
 is `zig_build` and it runs `zig build`.  The other options are:
  * `:compiler zig_test` which runs `zig test` on the current file.

autoload/zig/fmt.vim

@@ -69,7 +69,12 @@ function! zig#fmt#Format() abort
 
   if err != 0
     echohl Error | echomsg "zig fmt returned error" | echohl None
-    return
+    if get(g:, 'zig_fmt_autoswitch', 1)
+      return
+    else
+      wincmd p
+      return
+    endif
   endif
 
   " Run the syntax highlighter on the updated content and recompute the folds if