fix(install\_software.sh): add installation of kubectl using curl and make it available system-wide

feat(install\_software.sh): improve script by checking if kubectl is already installed before attempting to install it again

install_software.sh

@@ -64,3 +64,11 @@ then
   rm -f pet_0.3.6_linux_amd64.deb
 fi  
 
+# install kubectl
+if ! command -v kubectl &> /dev/null
+then	
+  curl -LO "https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl"	
+  sudo install -o root -g root -m 0755 kubectl /usr/local/bin/kubectl
+  rm -f kubectl
+fi  
+