repo optimization needed

[xuancong84]

Thanks for making the repo! Your repo content size is 55MB but total size is 359MB. The reason is because every time when those big files gets updated, the difference costs tons of space.

If you wish you can:

1. gzip all json files
2. for those large files, delete them in git history, only keep the latest version
3. after Step 2, run "git reflog expire --expire=now --all && git gc --aggressive --prune=now" to perform garbage cleaning of your repo