Add production site setup guide and related install scripts

production/electrs-start-testnet

@@ -0,0 +1,19 @@
+#!/usr/local/bin/zsh
+cd /electrs
+source $HOME/.cargo/env
+export PATH=$HOME/.cargo/bin:$PATH
+
+until false
+do
+	cargo run \
+		--release \
+		--bin electrs \
+		-- \
+		-vv \
+		--network testnet \
+		--daemon-dir /bitcoin \
+		--http-addr '[::]:3002' \
+		--cookie 'user:pass' \
+		--precache-scripts /electrs/contrib/popular-scripts.txt
+	sleep 1
+done