Add hfs setup

doc/hfs_setup.txt

@@ -0,0 +1,36 @@
+HFS on Raspberry PI4
+==
+https://github.com/rejetto/hfs
+
+Installing Node 18
+--
+Download from https://nodejs.org/download/release/v18.19.0/
+wget https://nodejs.org/download/release/v18.19.0/node-v18.19.0-linux-armv7l.tar.gz
+
+Extract
+tar xf ./node-v18.19.0-linux-armv7l.tar.gz
+
+Add to ~/.bashrc
+'''
+PATH=$PATH:/opt/node-v18.19.0-linux-armv7l/bin
+'''
+
+Running HFS
+--
+'''
+npx hfs@0.51.2
+'''
+
+If error: 
+'''
+Error: Cannot find module '/root/.npm/_npx/<some path>/node_modules/fs-x-attributes/prebuilds/linux-arm.node'
+'''
+then:
+'''
+cd /opt
+mkdir fs-extended-attributes
+cd fs-extended-attributes
+npm i fs-extended-attributes
+cd /root/.npm/_npx/<some path>/node_modules/fs-x-attributes/prebuilds/
+ln -s /opt/fs-extended-attributes/node_modules/fs-extended-attributes/cli.js linux-arm.node
+'''