FEATURE: Show installable elements

[ludeeus]

Related to #102

For now show_installable does not do anything, personally I found it confusing to see all these elements.
It was added as a preparation to easy install elements from the tracker-card but I have given up on that.

As of now, I see two options:

• Add the logic back to present all elements.
• Remove the config option.

Add your reaction to this FR with:
👍 for "Add the logic back to present all elements."
👎 for "Remove the config option."
🚀 for "I don't have an opinion"

[elRadix]

please add this feature, I want to see all items so that I can try them and discover new ones something like a custom card/component store 😄

[ludeeus]

@elRadix I will not add this to this component, but that is in the scope of "HACS"

It's funny that you wrote this 10 min before I posted #117