Buildguide and Makefile updates (#617)

* Buildguide and Makefile updates

* Removed package-lock removal

Makefile

@@ -33,7 +33,7 @@ ubuntu.img:
 	unxz ubuntu.img.xz
 
 product_key.txt:
-	/usr/bin/echo -ne "X\c" > product_key.txt
+	$(which echo) -n "X" > product_key.txt
 	cat /dev/random | base32 | head -c11 | tr '[:upper:]' '[:lower:]' >> product_key.txt
 	echo >> product_key.txt
 

build/README.md

@@ -2,12 +2,48 @@
 
 ## Prerequisites
 
-TODO
+1. Install dependences - The commands given assume a Debian or Ubuntu-based environment
+
+- Rust
+	`curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh`
+	https://rustup.rs
+- Avahi
+	`apt install avahi`
+	Installed by default on most Debian systems - https://avahi.org
+- Docker
+	`apt install docker.io`
+	https://docs.docker.com/get-docker
+- Node
+	`apt install nodejs`
+	https://nodejs.org/en/docs
+- NPM
+	`npm install -g npm`
+	https://docs.npmjs.com/downloading-and-installing-node-js-and-npm
+- jq
+	`apt install jq`
+	https://stedolan.github.io/jq
+
+2. Clone the repo and move into it
+
+```
+git clone --recursive https://github.com/Start9Labs/embassy-os.git`
+cd embassy-os
+```
 
 ## Build
+
 ```
 make
 ```
 
+## Flash
+
+Flash the resulting `eos.img` to your SD Card (16GB required, any larger is neither necessary, nor advantageous)
+
+We recommend [Balena Etcher](https://www.balena.io/etcher/)
+
 ## Setup
-http://embassy.local
+
+Visit http://embassy.local from any web browser
+
+We recommend [Firefox](https://www.mozilla.org/en-US/firefox/browsers