expand readme

Readme.md

@@ -6,7 +6,8 @@ This is heavy work in progress.
 
 ## Development setup
 
-This project uses `dep` with the `vendor/` dir in `.gitignore`.
+This project uses [`dep`](https://golang.github.io/dep/) with the `vendor/` dir
+in `.gitignore`.
 
 Once you have `dep` installed, run:
 
@@ -14,8 +15,21 @@ Once you have `dep` installed, run:
 dep ensure
 ```
 
+Next, you'll need a recent version of [Measurement Kit](http://github.com/measurement-kit).
+As this is a work in progress, you'll likely need to build a version of the
+library from source.
+
 You should then be able to build a ooni binary by running:
 
 ```
 make build
 ```
+
+
+If you want to build gooni against a development version of MK without
+installing it to your system, you can explicitly specify the path where MK
+was built as
+
+```
+CGO_LDFLAGS="-L/path/to/measurement-kit/.libs/" CGO_CFLAGS="-I/path/to/measurement-kit/include" make build
+```