How to enable PDO is undocumented

[divinity76]

Affected page
https://www.php.net/manual/en/pdo.installation.php

Issue description

How to enable PDO is undocumented.

Steps to reproduce

1. disable everything with --disable-all
2. enable pdo-sqlite
3. ./configure --disable-all --with-pdo-sqlite results in:

configure: error: 
You've configured extension pdo_sqlite, which depends on extension pdo,
but you've either not enabled pdo, or have disabled it.

Suggested fix
document how to explicitly enable pdo in https://www.php.net/manual/en/pdo.installation.php

Through trial-and-error, I have deduced that the correct flag is --enable-pdo , this works:

./configure --disable-all --enable-cli --enable-pdo --with-pdo-sqlite

But the problem is that I had to guess the flag, it appears to be undocumented.

(And it wasn't even my first guess, given that pdo-sqlite is --with-pdo-sqlite, my first guess was --with-pdo , which does not work.)