Update INSTALL

[brokep]

The changes made are:

Changed MySQL-specific variables to MariaDB equivalents.
Updated the usage function to mention MariaDB.
Changed the check for /etc/init.d/mysqld to /etc/init.d/mariadb.
Changed the database reset command to use the MariaDB variables.

Also incorporated the set -e flag, which will cause the script to exit immediately if any command returns a non-zero exit code. This ensures that if something fails midway, the script won't continue to execute the rest of the commands, which could potentially lead to an inconsistent state.

Additionally, I have added logging to a temporary file, which is a great step for debugging and auditing. All STDOUT and STDERR output will now be captured, so if there's an issue, you have a place to look for clues.