The internal links inside installation/install-fluent-package were broken

[livekn]

Describe the bug

The internal links were broken because it's inside "/installation/install-fluent-package", so should use "../../" instead of "../"

Link to the problematic documentation

https://docs.fluentd.org/installation/install-fluent-package/install-by-rpm-fluent-package
https://docs.fluentd.org/installation/install-fluent-package/install-by-deb-fluent-package
https://docs.fluentd.org/installation/install-fluent-package/install-by-dmg-fluent-package
https://docs.fluentd.org/installation/install-fluent-package/install-by-msi-fluent-package

Expected explanation

The link should work

Additional context

No response

[kenhys]

Thanks!
If you afford to fix it, Pull request is wellcome.

[livekn]

Update: all the internal links inside these pages were broken. I fix them all

[daipom]

Thanks so much!