Add button to create local calendar in calendar panel

[bramkragten]

Proposed change

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New feature (thank you!)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Example configuration

Additional information

• This PR fixes or closes issue: fixes #
• This PR is related to issue or discussion:
• Link to documentation pull request:

Checklist

• The code change is tested and works locally.
• There is no commented out code in this PR.
• Tests have been added to verify that the new code works.

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated for www.home-assistant.io

[piitaya]

Should we add some margin at the bottom? It feel weird and cropped (even it's not the case)

[bramkragten]

We can make it higher, I think adding margin is a bit weird

[piitaya]

I think it's because of the username not aligned next to it. But we can improve the design during beta.