### What changes were proposed in this pull request?
Fix a few super nit problems
### Why are the changes needed?
To make doc look better
### Does this PR introduce any user-facing change?
Yes
### How was this patch tested?
Tested using jykyll build --serve
Closes#27332 from huaxingao/spark-30575-followup.
Authored-by: Huaxin Gao <huaxing@us.ibm.com>
Signed-off-by: Takeshi Yamamuro <yamamuro@apache.org>