add bolt card guide

boltcard/README.md

@@ -0,0 +1,55 @@
+## Tools used
+* Card: NXP NTAG424 DNA https://zipnfc.com/nfc-pvc-card-credit-card-size-ntag424-dna.html
+* Raspiblitz node running:
+* Core Lightning
+* LNbits with the Bolt Cards extension
+* Boltcard NFC Card Creator Android app
+
+## Preparation
+
+### Run the latest experimental version of Raspiblitz
+* `menu` -> `PATCH `
+* `REPO`: rootzoll
+* `BRANCH`: dev
+
+### To update LNbits to the latest commit in the master branch
+* Run:
+```
+config.scripts/bonus.lnbits.com sync
+```
+### Expose LNbits on a public domain
+* can use a cheap, minimal VPS tunneled from the node with Tailscale
+* point an A-record with a subdomain to the public IPaddress of the VPS
+* download Tailscale on the node and the VPS: https://tailscale.com/download/linux
+* log in on both (consider using a dedicated github account)
+* on the VPS set up nginx to forward a subdomain to the TailscaleIP:LNbitsPORT on the node: https://github.com/openoms/bitcoin-tutorials/tree/master/nginx
+
+### Download the Boltcard NFC Card Creator Android app
+ * https://play.google.com/store/apps/details?id=com.lightningnfcapp
+ * https://github.com/boltcard/bolt-nfc-android-app
+
+
+## Steps to set up a Bolt Card
+* open LNbits on the public domain
+* create a wallet and save the link
+* add the Bolt Cards extension (to serve the boltcard API)
+* open the extension and create a bolt card
+* scan the QRcode with the keys with the Boltcard NFC Card Creator app
+* write the keys on a blank card by touching it to the phone
+
+The setup of the bolt card is complete!
+
+Don't forget to fund the LNbits wallet backing the card to be able to pay.
+
+## Test
+* Breez
+* Wallet of Satoshi (didn't work for me)
+* NFC enabled webwallet like the LNbits TPOS: https://clnbits.diynodes.com/tpos/gyZytJ3eLygXbe7EsJoi8C
+* NFC enabled PoS terminals
+
+Resources:
+* https://www.boltcard.org/
+* https://github.com/boltcard/boltcard
+* https://github.com/boltcard/bolt-nfc-android-app
+* https://github.com/lnbits/lnbits/tree/main/lnbits/extensions/boltcards
+* Post on stacker.news: https://stacker.news/items/81920