Documentation: fix formatting typo in pretty-formats.txt

A missing space messed up formatting of the `%(trailers)` format.

Signed-off-by: Junio C Hamano <[email protected]>

Author: asheiduk

Documentation/pretty-formats.txt

@@ -199,7 +199,7 @@ endif::git-rev-list[]
   than given and there are spaces on its left, use those spaces
 - '%><(<N>)', '%><|(<N>)': similar to '% <(<N>)', '%<|(<N>)'
   respectively, but padding both sides (i.e. the text is centered)
--%(trailers): display the trailers of the body as interpreted by
+- %(trailers): display the trailers of the body as interpreted by
   linkgit:git-interpret-trailers[1]
 
 NOTE: Some placeholders may depend on other options given to the