mdbook: `@` character limitation is gone
- Output object format must be ELF
- Custom linking (linker script) is required
- Single, global logger instance (but using multiple channels is possible)
-- The `@` character is not allowed in strings but otherwise UTF-8 is supported
- &#x1F44D;
- No x86 support. The x86 architecture is exclusively used for testing at the
moment.
