#4028 add agent service docs for snowflake agent Pull request opened by hhcs9527 Describe your changes Add agent service sample in snowflake plugin. Check all the applicable boxes ☑︎ I updated the documentation accordingly. ☐ All new and existing tests passed. ☑︎ All commits are signed-off. Screenshots Note to reviewers flyteorg/flyte ✅ All checks have passed 2/2 successful checks