Add Linux user to www-data group. Fix unable to edit files under /var/www/html/

add_linux_user_to_www_data_group.bash

# Add the current user to www-data group
sudo usermod -a -G www-data $USER

# Change the group of web server directory to www-data
sudo chgrp -R www-data /var/www/html

# Give write permission to the www-data group
sudo chmod -R g+w /var/www/html


# You may need to restart
# reboot


# References:
# https://www.digitalocean.com/community/questions/why-doesn-t-chown-r-root-www-data-work-on-my-wordpress-installation#answer_23969
# https://www.washington.edu/computing/unix/permissions.html