Make README less scabious

Signed-off-by: Justin Cormack <justin.cormack@docker.com>
(cherry picked from commit b2ad59e7bd78271223d0912b1717e63b269346d3)
Signed-off-by: Tibor Vass <tibor@docker.com>

man/README.md

@@ -8,7 +8,7 @@ Do *not* edit the man pages in the man1 directory. Instead, update the
 Cobra command or amend the Markdown files for legacy pages.
 
 
-## Generate the mange pages
+## Generate the man pages
 
 From within the project root directory run: