Add launchpad uninstaller prerm and postrm (#957)

Co-authored-by: Hien To <tominhhien97@gmail.com>

Author: hiento09

package-managers-template/launchpad/cortexso/debian/postrm

@@ -0,0 +1,10 @@
+#!/bin/sh
+set +e
+
+for userdir in /home/*; do
+  if [ -d "$userdir/cortex" ]; then
+    rm -rf "$userdir/cortex" > /dev/null 2>&1
+  fi
+done
+
+exit 0

package-managers-template/launchpad/cortexso/debian/prerm

@@ -0,0 +1,6 @@
+#!/bin/sh
+set +e
+
+/usr/bin/cortex stop > /dev/null 2>&1
+
+exit 0