document how to get a development setup

only `make` is essential, to fetch the custom codemirror code.

go/linguaevalia/README.md

[one for rust](./bin/run-rust)) or you can implement the `Language`
interface.
## Development setup
```
~ $ git clone git://github.com/heyLu/lp
~ $ cd lp/go/linguaevalia
~/lp/go/linguaevalia $ make               # download codemirror
~/lp/go/linguaevalia $ go run
```
Alternatively, replace `go run` with `qst linguaevalia.go`, to restart
the server automatically if `linguaevalia.go` changes.
## Contributions and feedback welcome!
Tell me what you do with it, when it helped you, what you're missing.