update readme with installation instructions

Author: robertDurst

README.md

@@ -6,6 +6,14 @@ The Sailfish programming language is an experimental project I am undertaking du
 
 ***
 
+## Installation
+
+For now, you must build from source:
+1. clone this repo
+2. `cd sailfishc`
+3. `make`
+4. `./sailfishc`
+
 ## Development
 
 To run tests, you'll need [GoogleTest](https://github.com/google/googletest) and [CMake](https://cmake.org). There is a nice tutorial on how to get GoogleTest up and running on Ubuntu [here](https://www.eriksmistad.no/getting-started-with-google-test-on-ubuntu/). Make sure it is in accessible directory, although I believe there exists a git submodule in the `libs` directory of this repo. In order to run the test suite, follow these steps: