some issues on Contributor Over Time

[juzhiyuan]

Hi, the previous issues I mentioned have been resolved, but I found some new issues.

1. Just to make sure, if the Merge button only works for APISIX repo?
2. The Share URL is too long... If I have 3+ repos, it's too long.
3. See https://contributor-graph-api.apiseven.com/contributors-svg?chart=contributorOverTime&repo=30-seconds/30-seconds-of-code,apache/apisix
   

It's ok for me to discuss those questions or issues in another PR.

Originally posted by @juzhiyuan in #37 (comment)