Move util-git documentation to duck.

doc/utils.md

@@ -139,34 +139,6 @@ Converts given number to a string with two-digit fractional
 part. Should the fractional part be 0, it is replaced with the string
 "--".
 
-### Git
-
-    (import util-git)
-
-This module provides basic git repository querying functionality.
-
-    (git repo [mode])
-
-* ```repo``` - a path to repository
-* ```mode``` - return values mode for operations
-
-Returns a procedure that allows invocation of git in given ```repo```
-repository returning one or two values based on ```mode``` given:
-
-* ```#:exit``` - returns exit code
-* ```#:output``` - returns the output lines (default)
-* ```#:exit+output``` - returns both exit code and output lines
-
-    (git-status repo)
-
-* ```repo``` - git repository
-
-Returns a dictionary with the following keys:
-
-* ```'modified``` - list of modified files
-* ```'untracked``` - list of untracked files
-* ```'unknown``` - list of files with unknown status
-
 ### IO
 
     (import util-io)