Provide bash completion support file
Summary:
This fixes the following issue:
bash: /opt/arcanist/support/shell/hooks/../rules/bash-rules.sh: No such file or directory
Test Plan: arc shell on Dwellers
Reviewers: dereckson
Reviewed By: dereckson
Subscribers: Nasqueron Docker deployment squad
Tags: Docker images
Differential Revision: https://devcentral.nasqueron.org/D2348