Allow to generate a list of the scripts

Summary:
The rOPS 6fdba60540be commit documents how to generate a list
of the TCL scripts provided by this repository to be used in
our bots.

This change offers a make list command to get such a list instead.

Test Plan: make list -> P273

Reviewers: dereckson

Reviewed By: dereckson

Differential Revision: https://devcentral.nasqueron.org/D1288