Remove old files completely from git history

reduce_git_repo_size.sh

## How to remove the old files/folder from all git commits.

#1. clone the repo freshly
git clone <repo.git>

#2. Do index-filter option to go through all the object indexs and look for give match
#   And remove those matching objects.
git filter-branch \
--prune-empty \
--index-filter \
'git rm -rf --cached --ignore-unmatch <YOUR_FILE_OR_FOLDER_TO_BE_REMOVED>' \
--tag-name-filter cat -- --all

# 3. As git won't remove those objects really, it does unlink from the history.
#    We can avoid those removed object by cloning the repo again. Clone operation
#    Won't download the removed objects.

git clone file:///<path_to_repo>  <repo-trimmed>

# 4. Create a new project in github / other providers and push this new project on it.
#    As pushing to old repo itself won't remove the removed / unlinked objects.
#    Git is trying to keep the objects as much as possible.