Customize target and rel attributes for home layout

[wodeni]

Is your feature request related to a problem? Please describe.

Now that pathname protocol has been removed (5836fac), the home layout cannot emulate the behavior by specifying target and rel attributes of actions. In my case, I had been using pathname to link to an SPA hosted together with the main site, and was able to use target: "_blank" for the nav bar, but not the home page action (PR: penrose/penrose#1704).

Describe the solution you'd like

Just like the nav bar in config.ts, the actions of home layout exposes target and rel.

Describe alternatives you've considered

• Not using the default theme home layout but I'd love to keep using the default theme!
• Bring back pathname, which is unlikely
• Turn off cleanUrl, but this will impact the entire site, which is not desirable.

Additional context

Related issue on sidebar links: #2851

Validations

• Follow our Code of Conduct
• Read the docs.
• Read the Contributing Guidelines.
• Check that there isn't already an issue that asks for the same feature to avoid creating a duplicate.

[liana-p]

Implementing this, will open a PR for it soon