Merge pull request rust-lang#3412 from mathstuf/doc-typos

Configurations: fix typos and mismatches

Configurations.md

@@ -1664,7 +1664,7 @@ See also: [`space_after_colon`](#space_after_colon).
 The maximum diff of width between struct fields to be aligned with each other.
 
 - **Default value** : 0
-- **Possible values**: any positive integer
+- **Possible values**: any non-negative integer
 - **Stable**: No (tracking issue: #3371)
 
 #### `0` (default):
@@ -2177,7 +2177,7 @@ Maximum number of blank lines which can be put between items. If more than this
 lines are found, they are trimmed down to match this integer.
 
 - **Default value**: `1`
-- **Possible values**: *unsigned integer*
+- **Possible values**: any non-negative integer
 - **Stable**: No (tracking issue: #3381)
 
 ### Example
@@ -2327,7 +2327,7 @@ Copyright 2018 The Rust Project Developers.`, etc.:
 
 Skip formatting the specified files and directories.
 
-- **Default value**: format every files
+- **Default value**: format every file
 - **Possible values**: See an example below
 - **Stable**: No (tracking issue: #3395)