patchDocumentation/pretty-{formats,options}: better reference for "format:<string>"

> In "git help log" (and friends) it's not easy to find the possible
> placeholder for <string> for the "--pretty=format:<string>" option
> to git log.
>
> This patch makes the placeholder easier to find by adding a reference
> to the "PRETTY FORMATS" section and repeating the "format:<string>"
> phrase.
>
> Signed-off-by: Nazri Ramliy <ayiehere@gmail.com>

>  Documentation/pretty-formats.txt |    4 ++--
>  Documentation/pretty-options.txt |    5 +++--
>  2 files changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/Documentation/pretty-formats.txt b/Documentation/pretty-formats.txt
> index 1686a54..c85a52c 100644
> --- a/Documentation/pretty-formats.txt
> +++ b/Documentation/pretty-formats.txt
> @@ -76,9 +76,9 @@ displayed in full, regardless of whether --abbrev or
>  true parent commits, without taking grafts nor history
>  simplification into account.
>  
> -* 'format:'
> +* 'format:<string>'
>  +
> -The 'format:' format allows you to specify which information
> +The 'format:<string>' format allows you to specify which information
>  you want to show. It works a little bit like printf format,
>  with the notable exception that you get a newline with '%n'
>  instead of '\n'.
> diff --git a/Documentation/pretty-options.txt b/Documentation/pretty-options.txt
> index af6d2b9..d78e121 100644
> --- a/Documentation/pretty-options.txt
> +++ b/Documentation/pretty-options.txt
> @@ -3,8 +3,9 @@
>  
>  	Pretty-print the contents of the commit logs in a given format,
>  	where '<format>' can be one of 'oneline', 'short', 'medium',
> -	'full', 'fuller', 'email', 'raw' and 'format:<string>'.
> -	When omitted, the format defaults to 'medium'.
> +	'full', 'fuller', 'email', 'raw' and 'format:<string>'.  See
> +	the "PRETTY FORMATS" section for some additional details for each
> +	format.  When omitted, the format defaults to 'medium'.
>  +
>  Note: you can specify the default pretty format in the repository
>  configuration (see linkgit:git-config[1]).
> -- 
> 1.7.1.226.g770c5