feat: allow extra tools on custom homepage card

[clanghout]

Thanks a lot for this plugin! I like it a lot and am busy convincing my team we need this one in our backstage.

My feature request is that I added a custom tool to the toolbox and would like to be able to use it on the homepage via your plugin.

Happy to give this a try if you think this is feasible.

[drodil]

It makes a lot of sense, only problem is that there is no way to pass the extra tools through cardExtension in plugin.ts. Have to see if there's some workaround for this.

[clanghout]

hmm yeah that seems tricky indeed... dynamically loading components is hard to get right from my experience indeed.

as an FYI; I'm not in need of this feature so much anymore 😅 but that does not mean it cannot benefit others of course.

[bforbis]

FYI, I opened up a slightly different issue which might be a stopgap solution to this. It requires forking/ building your own homepage however.

#86