Update README.md

[faddat]

Updated readme with a link, information about flashing, and such.

[ScardracS-zz]

I found your guide a bit too simple:

1. You suggest to use jumprive present on ubports, but you are not sure if someone still have it or no: that's why jumpdrive made by @Danct12 exist and can be found here: https://github.com/dreemurrs-embedded/Jumpdrive/releases
2. Using dd if a bit risky and I suggest to add && sync in order to prevent errors during copy (I prefer to suggest to use gnome-disk-utility if you are in linux, it's faster compared to etcher and safer compared to dd)

[ScardracS-zz]

And, to be clear: mine is not a criticism, just a personal point of view

[faddat]

Hey no worries.

I had better ask some questions about jump drive in discord.

Arch on my phone is great.