Documentation updates.

Fill in more missing documentation.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

Documentation/git-diff.txt

@@ -3,25 +3,39 @@ git-diff(1)
 
 NAME
 ----
-git-diff - Some git command not yet documented.
+git-diff - Show changes between commits, commit and working tree, etc.
 
 
 SYNOPSIS
 --------
-'git-diff' [ --option ] <args>...
+'git-diff' [ --diff-options ] <ent>{0,2} [<path>...]
 
 DESCRIPTION
 -----------
-Does something not yet documented.
-
+Show changes between two ents, an ent and the working tree, an
+ent and the index file, or the index file and the working tree.
+The combination of what is compared with what is determined by
+the number of ents given to the command.
+
+`----------------`--------`-----------------------------`------------------
+Number of ents    Options  What's Compared               Underlying command
+---------------------------------------------------------------------------
+0                 -        index file and working tree   git-diff-files
+1                 --cached ent and index file            git-diff-index
+1                 -        ent and working tree          git-diff-index
+2                 -        two ents                      git-diff-tree
+---------------------------------------------------------------------------
 
 OPTIONS
 -------
---option::
-	Some option not yet documented.
-
-<args>...::
-	Some argument not yet documented.
+--diff-options::
+	'--diff-options' are passed to the `git-diff-files`,
+	`git-diff-index`, and `git-diff-tree` commands.  See the
+	documentation for these commands for description.
+
+<path>...::
+	The <path> arguments are also passed to `git-diff-\*`
+	commands.
 
 
 Author

Documentation/git-format-patch.txt

@@ -3,25 +3,56 @@ git-format-patch(1)
 
 NAME
 ----
-git-format-patch - Some git command not yet documented.
+git-format-patch - Prepare patches for e-mail submission.
 
 
 SYNOPSIS
 --------
-'git-format-patch' [ --option ] <args>...
+'git-format-patch' [-n][-o <dir>][-k][--mbox][--diff-options] <his> [<mine>]
 
 DESCRIPTION
 -----------
-Does something not yet documented.
+Prepare each commit with its patch since <mine> head forked from
+<his> head, one file per patch, for e-mail submission.  Each
+output file is numbered sequentially from 1, and uses the first
+line of the commit message (massaged for pathname safety) as the
+filename.
+
+When -o is specified, output files are created in that
+directory; otherwise in the current working directory.
+
+When -n is specified, instead of "[PATCH] Subject", the first
+line is formatted as "[PATCH N/M] Subject", unless you have only
+one patch.
+
+When --mbox is specified, the output is formatted to resemble
+UNIX mailbox format, and can be concatenated together for
+processing with applymbox.
 
 
 OPTIONS
 -------
---option::
-	Some option not yet documented.
+-o <dir>::
+	Use <dir> to store the resulting files, instead of the
+	current working directory.
+
+-n::
+	Name output in '[PATCH n/m]' format.
+
+-k::
+	Do not strip/add '[PATCH]' from the first line of the
+	commit log message.
+
+--author, --date::
+	Output From: and Date: headers for commits made by
+	yourself as well.  Usually these are output only for
+	commits made by people other than yourself.
 
-<args>...::
-	Some argument not yet documented.
+--mbox::
+	Format the output files for closer to mbox format by
+	adding a phony Unix "From " line, so they can be
+	concatenated together and fed to `git-applymbox`.
+	Implies --author and --date.
 
 
 Author

Documentation/git-stripspace.txt

@@ -3,7 +3,7 @@ git-stripspace(1)
 
 NAME
 ----
-git-stripspace - Fileter out empty lines.
+git-stripspace - Filter out empty lines.
 
 
 SYNOPSIS

Documentation/git.txt

@@ -237,10 +237,18 @@ link:git-commit.html[git-commit]::
 	Record changes to the repository.
 	Previously this command was known as git-commit-script.
 
+link:git-diff.html[git-diff]::
+	git-diff.
+	Previously this command was known as git-diff-script.
+
 link:git-fetch.html[git-fetch]::
 	Download from a remote repository via various protocols.
 	Previously this command was known as git-fetch-script.
 
+link:git-format-patch.html[git-format-patch]::
+	git-format-patch.
+	Previously this command was known as git-format-patch-script.
+
 link:git-log.html[git-log]::
 	Shows commit logs.
 	Previously this command was known as git-log-script.
@@ -391,19 +399,12 @@ link:git-send-email.html[git-send-email]::
 link:git-show-rev-cache.html[git-show-rev-cache]::
 	Show the contents of a rev-cache file.
 
-Commands not yet documented
----------------------------
-
-link:git-diff.html[git-diff]::
-	git-diff.
-	Previously this command was known as git-diff-script.
+link:git-stripspace.html[git-stripspace]::
+	Filter out empty lines.
 
-link:git-format-patch.html[git-format-patch]::
-	git-format-patch.
-	Previously this command was known as git-format-patch-script.
 
-link:git-stripspace.html[git-stripspace]::
-	git-stripspace.
+Commands not yet documented
+---------------------------
 
 link:gitk.html[gitk]::
 	gitk.