Fixed unnecessary sandboxes docs header

Sandboxes.md

@@ -1,5 +1,3 @@
-# Sandboxes
-
 Coyote can launch itself inside an isolated **Docker Sandbox** (`sbx`) with one command. This gives you a disposable, 
 hypervisor-isolated environment where Coyote runs against your project workspace without having access to the rest of 
 your host machine.