Update wording in regards to MySQL database

[Ov3rfly]

Since a while WordPress is also able to work with MariaDB.

People now use MariaDB for new sites or change their existing sites to MariaDB for various reasons.

Currently wp-config-sample.php and also the instructions how to use it, contain many references to MySQL like MySQL database username, MySQL hostname, Example MySQL username etc.

This leads to confusion, e.g. if MariaDB settings would be entered elsewhere or similar.

All references to MySQL should be adjusted to a more general wording or have added MariaDB in some general descriptions like MySQL settings - You can get this info from your web host.

​https://wordpress.org/support/article/editing-wp-config-php/

[audrasjb]

Shouldn't we just replace "MySQL" with "SQL" so the comments/instructions could be software-agnostic?
Or do we need deeper changes?

Trac ticket: https://core.trac.wordpress.org/ticket/54610

[audrasjb]

Since it's a docs-only ticket, let's consider introducing this change in 5.9.

Plus, it would makes sense with [52319].

[audrasjb]

Related: #41490

[hellofromTonya]

Marking ​PR 2045 for commit.

Changes MySQL to Database settings, which refers to either MySQL or MariaDB.

[audrasjb]

In 52367:

Docs: Use generic references to "Database" in wp-config-sample.php.

This replaces the references to "MySQL" info in the WordPress configuration sample file. Using the generic term "Database" now refers to either MySQL or MariaDB.

Props Ov3rfly, audrasjb, hellofromTonya.
Fixes #54610.

Committed in https://core.trac.wordpress.org/changeset/52367

[johnbillion]

In 52423:

Docs: Further corrections and improvements to the inline documentation for wpdb.

See #53399, #54610