Update packedGit config option documentation.
Update packedGit config option documentation.

Corrected minor typos and documented the new k/m/g suffix for
core.packedGitWindowSize and core.packedGitLimit.

[jc: with a minor markup fix.]

Signed-off-by: Shawn O. Pearce <f01032651c12a22b2103346ba96b3b6b231f9d3c@spearce.org>
Signed-off-by: Junio C Hamano <dc50d1021234060e53ec42a77d526afa2fe07479@cox.net>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git