add redis to path code example

Example 1: how to install redis in ubuntu

sudo apt update
sudo apt install redis-server

sudo nano /etc/redis/redis.conf

# change "supervised no" to "supervised systemd" 
supervised systemd

sudo systemctl restart redis.service

sudo systemctl status redis

redis-cli

Example 2: restart redis ubuntu

# restart redis service
sudo service redis-server restart

# stop redis service
sudo service redis-server stop

Example 3: redis cache start

sudo /etc/init.d/redis_6379 start

Example 4: install redis

sudo systemctl restart redis.service