Remove reviewer section from PR template
Remove reviewer section from PR template

ashigeru/asakusafw-m3bp,asakusafw/asakusafw-m3bp,asakusafw/asakusafw-m3bp,asakusafw/asakusafw-m3bp,ashigeru/asakusafw-m3bp,ashigeru/asakusafw-m3bp