feat(run): toggle trace logs with environment variable (#59)

Now you can enable trace logs via setting the `DEBUG` variable to a value.

It is also now disabled as default.

closes #60

README.md

@@ -20,6 +20,7 @@ This action generates a changelog based on your Git history using [git-cliff](ht
 ### Environment variables
 
 - `OUTPUT`: Output file. (Default: `"git-cliff/CHANGELOG.md"`)
+- `DEBUG`: Set to a not empty value (e.g. `"true"`) to print executed commmands. (Default: `unset`)
 
 > [!IMPORTANT]
 > Check out the entire history via `fetch-depth: 0` before running this action.

run.sh

@@ -1,6 +1,10 @@
 #!/bin/bash
 
-set -uxo pipefail
+if [[ -n "$DEBUG" ]]; then
+    set -x
+fi
+
+set -uo pipefail
 
 # Avoid file expansion when passing parameters like with '*'
 set -o noglob