README update: features and planned features

[newtonick]

Many of the planned features listed were prior to release 0.6.0. This PR updates this list to move some of the past planned features to be highlighted features.

Highlighted features added:

• Single-sig and multi-sig change address verification
• Taproot (P2TR) single-sig signing
• Customized Linux live-boot OS to allow MicroSD card removal

Planned features added:

• Single-sig change address verification via output descriptor
• PSBT signing via microSD card

See README file diff for complete list of changes. Please provide feedback on what to add/remove/change in the "Feature Highlights" to "Planned Upcoming Improvements" section of the README.

[Marc-Gee]

I suggest to remove this now. Thats a given now.

[Marc-Gee]

Add as a separate/new feature lines:

• Seedsigner_OS is a live-boot OS allowing your MicroSD card to be physically removed after starting, before your Private keys are even input or scanned, to further improve our air-gapping around your Private keys.

• Our absolute minimum surface-area Linux OS removes all Wifi, Bluetooth USB and swap libraries at the Linux Kernel level.
  (Removed or just disabled???)

• BIP-85 deterministic seed derivation is now supported.

• Massively Improved startup time of <15 seconds on Pi Zero 2 !

• Super-small image files of under 42 Megabytes allows the use of very cheap, small MicroSD cards. Yes, Megabytes, not Gigabytes!

• An active Telegram community to offer user support, suggestions and interesting discussions.

• Many other improvements, bugfixes and tweaks provided by our users feedback.

[Marc-Gee]

Suggest: "The startup time on the most affordable, (but slowest) hardware, (the Pi Zero V1.3) takes 45 seconds, but just 15 seconds on a the faster processor in the Pi Zero 2!
(Desobediente Tecnológico timed it himself with Seedsigner_os)

[Marc-Gee]

Compatible with these Wallet co-ordinator softwares: Specter Desktop, Sparrow Desktop, BlueWallet, Nunchuk and Keeper.

[Marc-Gee]

I have included in some of the new features and updates from the 060 releases page.

[jdlcdl]

ACK,

These read well and improve/update the docs. No problems with additions that Marc mentions above, all are valid.

[SeedSigner]

"Seedsigner_OS is a live-boot OS allowing your MicroSD card to be physically removed after starting, before your Private keys are even input or scanned, to further improve our air-gapping around your Private keys"

I'd like to see the last part of this re-worded to something like "for additional user assurance that private key information is not persisting on the signer's memory card" or something similar.

The microSD removal is more of a statelessness guarantee than it has to do with air-gapping.

[akarve]

For

seedsigner/README.md

Line 232 in 4793250

| DD Command Line Utility | Built-in to Linux and MacOS, the DD (Data Duplicator) is a tool for advanced users. If not used carefully it can accidentally format the incorrect disk! | Built-in to Linux and MacOS |

may I suggest that the docs add a specific example of how to flash with dd on MacOS? (I for one found it weird to trust a third-party tool (Balena) for this purpose when the OS supports it.)

MacOS users can flash the SD card as follows. Take caution to carefully read and verify these commands before running them. Failure to do so can result in permanent data loss.

1. Insert your SD card into your Mac
2. Ensure your SD card has a unique, recognizable name
3. Open Terminal in the directory that contains your SeedSigner OS image
4. Run diskutil list
5. Look for the name of your SD card, verify its size, and carefully copy down the
   mount point (something like dev/diskx)
6. Unmount your SD card with diskutil unmountdisk dev/diskx
7. Flash the SD card as follows. It should take just a few seconds.

   sudo dd if=seedsigner_os.0.6.0.pi0.img of=/dev/diskx bs=4M conv=fsync status=progress

[newtonick]

This PR is replaced by #402