tools: unify .editorconfig rules for 2-space

The `doc` directory had not had any editorconfig rules applied which can
lead to tab indentation in editors. This unifies the rules to use 2-space
as the default. Additionally, all rules are now sorted alphabetically.

PR-URL: https://github.com/nodejs/node/pull/23163


Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>