Fix #11 - add build documentation

BUILD.md

@@ -0,0 +1,23 @@
+Bulding MailHog
+===============
+
+MailHog is built using `make`, and using [this Makefile](Makefile).
+
+If you aren't making any code changes, you can install MailHog using
+`go get github.com/ian-kent/Go-MailHog`, since [assets.go](MailHog-UI/assets/assets.go)
+is already pre-compiled and committed to this repository.
+
+### Why do I need a Makefile?
+
+MailHog has HTML, CSS and Javascript assets which need to be converted
+to a go source file using [go-bindata](https://github.com/jteeuwen/go-bindata).
+
+This must happen before running `go build` or `go install` to avoid compilation
+errors (e.g., `no buildable Go source files in MailHog-UI/assets`).
+
+### go generate
+
+The build should be updated to use `go generate` (added in Go 1.4) to
+preprocess static assets into go source files.
+
+However, this will break backwards compatibility with Go 1.2/1.3.

README.md

@@ -44,6 +44,8 @@ Go was chosen for portability - MailHog runs without installation on multiple pl
 
 Clone this repository to ```$GOPATH/src/github.com/ian-kent/Go-MailHog``` and type ```make deps```.
 
+See the [Building MailHog](BUILD.md) guide.
+
 Requires Go 1.2+ to build.
 
 Run tests using ```make test``` or ```goconvey```.