Resync mysql, mariadb, and percona descriptions

mariadb/content.md

@@ -94,6 +94,10 @@ Do note that there is no need to use this mechanism to create the root superuser
 
 This is an optional variable. Set to `yes` to allow the container to be started with a blank password for the root user. *NOTE*: Setting this variable to `yes` is not recommended unless you really know what you are doing, since this will leave your MariaDB instance completely unprotected, allowing anyone to gain complete superuser access.
 
+# Initializing a fresh instance
+
+When a container is started for the first time, a new database `mysql` will be initialized with the provided configuration variables. Furthermore, it will execute files with extensions `.sh` and `.sql` that are found in `/docker-entrypoint-initdb.d`. You can easily populate your %%REPO%% services by [mounting a SQL dump into that directory](https://docs.docker.com/userguide/dockervolumes/#mount-a-host-file-as-a-data-volume) and provide [custom images](https://docs.docker.com/reference/builder/) with contributed data.
+
 # Caveats
 
 ## Where to Store Data

mysql/content.md

@@ -94,7 +94,7 @@ This is an optional variable. Set to `yes` to allow the container to be started
 
 # Initializing a fresh instance
 
-When a container is started for the first time, a new database `mysql` will be initialized with the provided configuration variables. Furthermore, it will execute `.sh`- and `.sql`-files that are found in `/docker-entrypoint-initdb.d`. You can easily populate your %%REPO%% services by [mounting a SQL dump into that directory](https://docs.docker.com/userguide/dockervolumes/#mount-a-host-file-as-a-data-volume) and provide [custom images](https://docs.docker.com/reference/builder/) with contributed data.
+When a container is started for the first time, a new database `mysql` will be initialized with the provided configuration variables. Furthermore, it will execute files with extensions `.sh` and `.sql` that are found in `/docker-entrypoint-initdb.d`. You can easily populate your %%REPO%% services by [mounting a SQL dump into that directory](https://docs.docker.com/userguide/dockervolumes/#mount-a-host-file-as-a-data-volume) and provide [custom images](https://docs.docker.com/reference/builder/) with contributed data.
 
 # Caveats
 

percona/content.md

@@ -94,6 +94,10 @@ Do note that there is no need to use this mechanism to create the root superuser
 
 This is an optional variable. Set to `yes` to allow the container to be started with a blank password for the root user. *NOTE*: Setting this variable to `yes` is not recommended unless you really know what you are doing, since this will leave your Percona instance completely unprotected, allowing anyone to gain complete superuser access.
 
+# Initializing a fresh instance
+
+When a container is started for the first time, a new database `mysql` will be initialized with the provided configuration variables. Furthermore, it will execute files with extensions `.sh` and `.sql` that are found in `/docker-entrypoint-initdb.d`. You can easily populate your %%REPO%% services by [mounting a SQL dump into that directory](https://docs.docker.com/userguide/dockervolumes/#mount-a-host-file-as-a-data-volume) and provide [custom images](https://docs.docker.com/reference/builder/) with contributed data.
+
 # Caveats
 
 ## Where to Store Data