Extend contributing guide with information on how to engage with the project

[rochaporto]

Description

The existing contributing guide has the required information for someone wanted to push a change:
https://lima-vm.io/docs/community/contributing/

It could be improved by adding additional information for people interested in the project and willing to contribute for:

• Getting engaged with the community of the project (introduce yourself)
• Learn where work is required
• Find open issues where help is needed

[afbjorklund]

1. "Introduce yourself", is probably best on the Slack (chat) channel?

https://lima-vm.io/docs/community/#communication-channels

• User stories: please share how your organization is adopting Lima #2390

2. "Learn where work is required"

https://lima-vm.io/docs/community/roadmap/ which now leads to "roadmap" label:

https://github.com/lima-vm/lima/issues?q=is%3Aissue+is%3Aopen+label%3Aroadmap

https://github.com/lima-vm/lima/discussions/categories/ideas (or any other category)

3. "Find open issues where help is needed"

I think we should be able to use the "help wanted" label to find issues:

https://github.com/lima-vm/lima/issues?q=is%3Aissue%20state%3Aopen%20label%3A%22help%20wanted%22

Possibly combined with the "good first issue" label, for newcomers...
And similarly to avoid the "expert" label, unless looking for a challenge.

Other bigger things are probably better for roadmap and for discussions?

[vishalanarase]

I'm interested to work on this issues, If things are finalized.