Add .mailmap file to calculate commits from different emails of same contributor together

[lysliu]

Contributors lost hist contribution log when email invalid

For some reasons, contributors switched his email.

Contributions were calculated by the email in commits, e.g.

## https://github.com/confidential-containers/cloud-api-adaptor/commit/c7c2a93501edf9bd469b5d4736301c6cfd7b3f0b.patch

From c7c2a93501edf9bd469b5d4736301c6cfd7b3f0b Mon Sep 17 00:00:00 2001
From: Yan Song Liu <[email protected]>
Date: Tue, 30 Jul 2024 14:56:23 +0800
Subject: [PATCH] tests/e2e: fix TestLibvirtKbsKeyRelease skip make align with
 test/e2e/main_test.go#L106

Signed-off-by: Yan Song Liu <[email protected]>

How to calculate different emails together

This can be done by add .mailmap file in the root folder of the repository
The content like below, Alice used 2 email submit commits.

Alice Realname <[email protected]>
Alice Realname <[email protected]>

• If the maintainers agree to add .mailmap file, then
• Contributors who used more than one email, please add comments below
• Any questions or suggestions on this?