update weight initialization

Author: skywind3000

README.md

@@ -141,7 +141,7 @@ Then you can open the menu by pressing space twice. If the 4th parameter `filety
 call quickui#menu#install('&C/C++', [
             \ [ '&Compile', 'echo 1' ],
             \ [ '&Run', 'echo 2' ],
-            \ ], -1, 'c,cpp')
+            \ ], '<auto>', 'c,cpp')
 ```
 
 This `C/C++` menu will be visible only if the `filetype` of current buffer is `c` or `cpp`.

autoload/quickui/menu.vim

@@ -140,9 +140,7 @@ function! quickui#menu#install(section, content, ...)
 	endif
 	if a:0 > 0 && has_key(current, a:section)
 		if type(a:1) == v:t_number
-			if a:1 >= 0
-				let current[a:section].weight = a:1
-			endif
+			let current[a:section].weight = a:1
 		endif
 	endif
 	if a:0 > 1 && has_key(current, a:section)