docs/specification/appnote.txt is non-distributable

### Describe the bug

docs/specification/appnote.txt's license does not allow one to distribute it. Please remove it.

### Reproduction Code

_No response_

### Steps to reproduce

Read 1.4.2

### Expected behavior

Should not be in this repo.

### Operating System

_No response_

### Framework Version

_No response_

### Tags

_No response_

### Additional context

_No response_