adding gitleaks pre commit hook (#22)

.pre-commit-config.yaml

@@ -0,0 +1,5 @@
+repos:
+  - repo: https://github.com/gitleaks/gitleaks
+    rev: v8.18.2
+    hooks:
+      - id: gitleaks

Makefile

@@ -9,3 +9,7 @@ sandbox:
 unit-test:
 	TESTING=true go test -v ./test
 	rm -rf test/dotctl_test 2> /dev/null
+
+pre-commit-hooks:
+	pre-commit autoupdate
+	pre-commit install