Enable cron-based nightly testing and small changes to workflows README

.github/workflows/README.md

@@ -1,3 +1,4 @@
+
 # Autotester2 (AT2) SNL Workflow for MAM4xx
 
 This document contains a brief description of how AT2 is used to automate
@@ -47,13 +48,17 @@ also by a handful of actions on such a PR that is already open, including:
 The workflow may also be run manually by members of the `snl-testing`
 team--that is, via
 
-> **Actions** -> `<SNL-AT2 Workflow Run/Job>` -> **Re-run `[all,this]` job(s)**.
+> **Actions** -> **SNL-AT2 Workflow** -> **Run Workflow** -> *Choose Branch from Dropdown Menu*.
+
+or
+
+> **Actions** -> `<Previously-run SNL-AT2 Workflow/Job>` -> **Re-run `[all,this]` job(s)**.
 
 The AT2 configuration on `blake` currently attempts to keep 3 runners available
 to accept jobs at all times.
 This workflow is configured to allow concurrent testing, so up to 3 test-matrix
 configurations can run at once.
-The concurrencty setting is also configured to kill any active job if another
+The concurrency setting is also configured to kill any active job if another
 instance of this workflow is started for the same PR ref.
 
 ##### Other Types of Job Control
@@ -75,7 +80,6 @@ The above is according to Mike's current understanding of AT2 and may contain
 minor inaccuracies.
 This will be updated accordingly upon confirmation.
 
-
 ## Development Details
 
 Most of the required configuration is provided by the AT2 docs and

.github/workflows/at2_snl.yml

@@ -20,9 +20,9 @@ on:
   # Manual run
   workflow_dispatch:
 
-  # # Add schedule trigger for nightly runs at midnight MT (Standard Time)
-  # schedule:
-  #   - cron: '0 7 * * *'  # Runs at 7 AM UTC, which is midnight MT during Standard Time
+  # Add schedule trigger for nightly runs at midnight MT (Standard Time)
+  schedule:
+    - cron: '0 22 * * *'  # Runs at 7 AM UTC, which is midnight MT during Standard Time
 
 concurrency:
   # Two runs are in the same group if they are testing the same git ref