improve readme (current status, building it yourself).

go/README.md

## qst - run things quickly (and easily)
intended to be run in unfamilar environments, might detect the project
type and everything later, for now you pass it a file and it will decide
what to do with it.
intended to be run in unfamilar environments, you pass it a file or a
directory and it tries to detect what it is and how to run it.
- run `qst` or `qst -h` to see options and support project types
- `qst hello_world.go`: compiles and runs `hello_world.go`, rerunning
	after it exits or the file is saved
	quite fun for small things, just throw some code in a file, have `qst`
	watch and restart when appropriate.
- the future: just run `qst` and it will run the first thing it detects
- `qst -phase=test ...` runs the tests for projects that support it
### Building it yourself
	# set up $GOPATH as desired
	$ export GOPATH=$PWD/.go         # choose whatever you want
	$ go build qst
	...
	$ ./qst -h
	Usage: qst <file>
	...
	$ ./qst examples/hello_web.rb
	...
	^C
	$ ./qst examples/hello_web.go
	...
Try changing something in the files, it's fun. :)