Add upgrade instructions for MariaDB

Added instructions for upgrading MariaDB to version 11.8 LTS.

Author: arhimede

docs/book/v2/faq.md

@@ -166,6 +166,45 @@ Being installed as a system package, it can be updated using the command which u
 ```shell
 sudo dnf upgrade -y
 ```
+## How do I upgrade MariaDB ?
+
+By default, MariaDB is at version 11.4 LTS. 
+In case you want to upgrade to a different version, for instance [11.8 LTS](https://mariadb.org/11-8-is-lts/), use the below steps:
+
+- Open the MariaDB.repo file in any text editor.
+```shell
+sudo nano /etc/yum.repos.d/MariaDB.repo
+```
+- Modify the **baseurl** variable to match the desired version, for instance `11.8` instead of `11.4`. 
+- Clean dnf cache
+```shell
+sudo dnf clean all
+```
+
+- Stop MariaDB
+```shell
+sudo systemctl stop mariadb
+```
+
+- Upgrade MariaDB
+```shell
+sudo dnf update -y
+```
+
+- Start MariaDB
+```shell
+sudo systemctl start mariadb
+```
+
+- Upgrade databases
+```shell
+sudo mariadb-upgrade -uroot -p
+```
+
+- Restart MariaDB
+```shell
+sudo systemctl restart mariadb
+```
 
 ## How do I create command aliases?