Add Henry Wang as a containerd reviewer

[estesp]

Henry has been making solid contributions to containerd for some time. Recently he has been providing significant help to the project reviewing PRs. Due to this sustained beneficial activity, I am proposing Henry as a reviewer for the project.

• [x] @henry118
• [x] @AkihiroSuda
• [ ] @crosbymichael
• [x] @dmcgowan
• [x] @estesp
• [ ] @stevvooe
• [ ] @dchen1107
• [ ] @Random-Liu
• [x] @mikebrow
• [ ] @yujuhong
• [x] @fuweid
• [ ] @mxpv
• [x] @dims
• [ ] @kevpar
• [x] @kzys
• [x] @samuelkarp

[mikebrow]

5 committer LGTM required (1/3 of 15 committers) + new reviewer (@henry118)