Unsupported examples

[tqrahman]

What is is PR for?

• Code update
• Documentation update
• Infrastructure update

What does this PR do?
Removed examples that the CDP wouldn't support. Removed 3d print files for enclosures.

Is this related to an open issue?
#376
#378
#417

Testing methodology
Nothing to test. No code was changed. Examples were removed and readmes' were updated.

Additional context
Add any other technical detail or considerations here.

Checklist
Before you submit this pull request, please make sure you have done the following:

General

• Contribution Guidelines: Have you read the contribution guidelines?
• Code of Conduct: Have you read the code of conduct?
• Documentation: If applicable, have you added or updated all relevant documentation?

For Code Updates

• Hardware Validation: If relevant, have you validated your changes on actual supported Duck hardware?
• Unit Tests: Have you run the unit tests on the device?
• Network Testing: If applicable, have you tested your changes on a Duck network?
• Licensing: Have you added a copyright and license header to each new file?

Tested Targets (Please check all that apply)

• All
• Heltec LoRa v3
• Heltec LoRa v2
• Heltec CubeCell Series
• TTGO T-Beam (SX1262)
• Others