Maintaining an html branch

[Christos Trochalakis <yatiohi@ideopolis.gr>]

Hello,

I would like to maintain an html branch for my repo, containing files
under my '_site/' dir that is not version controlled.

Below is a first draft that works, but as I am not really familiar
with git plumbing, I'd appreciate any comments on a better way or
style to to write it.

#!bash
jekyll --no-auto             # build the static website on _site/ dir
rm .git/html.index
export GIT_INDEX_FILE=.git/html.index
git add -f _site
tree_id=$(git write-tree --prefix=_site/)
new_commit=$(echo "New website"|git commit-tree $tree_id -p html)
git update-ref html $new_commit
rm .git/html.index

Thanks,
Chris