chore: move add-ns.py to a tilt directory

it's used only for tilt, and I prefer keeping the root directory a bit more organised

Author: Shesekino

Tiltfile

@@ -7,7 +7,7 @@ docker_build("snyk/kubernetes-monitor", ".",
 )
 
 allow_k8s_contexts(['minikube', 'kubernetes-admin@kind'])
-k8s_yaml(local("helm template snyk-monitor | ./add-ns.py snyk-monitor"))
+k8s_yaml(local("helm template snyk-monitor | ./tilt/add-ns.py snyk-monitor"))
 k8s_resource('snyk-monitor', port_forwards='9229:9229')
 watch_file("snyk-monitor")