What type of PR is this?

Uncomment only one /kind <> line, hit enter to put that in a new line, and remove leading whitespaces from that line:

/kind bug

What does this PR do / why do we need it:
Fix boost docs problems.

Which issue(s) this PR fixes:

Fixes #
boost API注释问题
https://e.gitee.com/mind_spore/issues/list?issue=I4AA1Q
[MS]build_train_network api document need optimize.
https://e.gitee.com/mind_spore/issues/list?issue=I49Q78
Special notes for your reviewers: