Add zen15_cleaner to custom_integrations

[NathanWatson]

Proposed change

Type of change

• [ ] Add a new logo or icon for a new core integration
• [ ] Add a missing icon or logo for an existing core integration
• [X] Add a new logo or icon for a custom integration (custom component)
  • [X] I've added a link to my custom integration repository in the PR description
• [ ] Replace an existing icon or logo with a higher quality version
• [ ] Replace an existing icon or logo after a branding change
• [ ] Removing an icon or logo

Additional information

• This PR fixes or closes issue: fixes #
• Link to code base pull request:
• Link to documentation pull request:
• Link to integration documentation on our website:
• Link to custom integration repository: https://github.com/NathanWatson/HA-ZEN15-Cleaner

Checklist

• [X] The added/replaced image(s) are PNG
• [X] Icon image size is 256x256px (icon.png)
• [X] hDPI icon image size is 512x512px for ([email protected])
• [X] Logo image size has min 128px, but max 256px, on the shortest side (logo.png)
• [X] hDPI logo image size has min 256px, but max 512px, on the shortest side ([email protected])