Update file doc/06-config.md

[adielcristo]

References

• https://github.com/composer/composer/blob/2.7.8/doc/06-config.md
• https://github.com/composer/composer/blob/2.6.6/doc/06-config.md
• https://github.com/composer/composer/blob/2.5.8/doc/06-config.md
• https://github.com/composer/composer/blob/2.4.4/doc/06-config.md
• https://github.com/composer/composer/blob/2.3.10/doc/06-config.md
• https://github.com/composer/composer/blob/2.2/doc/06-config.md
• https://github.com/composer/composer/blob/2.1.14/doc/06-config.md
• https://github.com/composer/composer/blob/2.0.14/doc/06-config.md
• https://github.com/composer/composer/blob/1.10/doc/06-config.md
• https://github.com/composer/composer/blob/1.9.3/doc/06-config.md
• https://github.com/composer/composer/blob/1.8.6/doc/06-config.md
• https://github.com/composer/composer/blob/1.7.3/doc/06-config.md
• https://github.com/composer/composer/blob/1.6.5/doc/06-config.md
• https://github.com/composer/composer/blob/1.5.6/doc/06-config.md
• https://github.com/composer/composer/blob/1.4.3/doc/06-config.md
• https://github.com/composer/composer/blob/1.3.3/doc/06-config.md
• https://github.com/composer/composer/blob/1.2.4/doc/06-config.md
• https://github.com/composer/composer/blob/1.1.3/doc/06-config.md
• https://github.com/composer/composer/blob/1.0.3/doc/06-config.md