Update README

Author: adamrtalbot

README.md

@@ -136,7 +136,7 @@ Default: The current GitHub repository (`https://github.com/${{github.repository
 
 A pipeline release tag, branch or commit hash.
 
-Default: The current GitHub commit hash (`github.sha`).
+Default: The revision specified in Tower or the default branch of the repo.
 
 ### `workdir`
 
@@ -307,19 +307,19 @@ The action prints normal stdout info-level log messages to the actions console.
 The output log file is saved as `tower_action_$(timestamp).log` and can be captured using `actions/upload-artifact using the following settings:
 
 ```yaml
-      - uses: actions/upload-artifact@v3
-        with:
-          name: Tower debug log file
-          path: tower_action_*.log
+- uses: actions/upload-artifact@v3
+  with:
+    name: Tower debug log file
+    path: tower_action_*.log
 ```
 
 The action writes a JSON file which has the same format as the `outputs.json` used above. This is wrtten to a file called `tower_action_$(uuidgen).json`. It can be captured in a similar manner:
 
 ```yaml
-      - uses: actions/upload-artifact@v3
-        with:
-          name: Tower output JSON file
-          path: tower_action_*.json
+- uses: actions/upload-artifact@v3
+  with:
+    name: Tower output JSON file
+    path: tower_action_*.json
 ```
 
 ## Credits