add install instructions

README.md

@@ -10,7 +10,22 @@ grep "pattern1|pattern2|pattern3" reference_file
 However, if you have a lot of patterns you want to match with GNU grep you will at some point hit the limits of argument length.
 Big grep uses a pattern file where each line is a pattern, and matches those 
 
-Note that compilation requires libboost-regex headers, because I wanted to be able to user Perl-style regexes and usually have boost available in all my environments.
+## Installation
+Note that compilation requires libboost-regex headers, because I wanted to be able to user Perl-style regexes and usually have boost available in all my environments (`libboost-regex-dev` on Ubuntu). 
+
+```bash
+# Clone
+git clone https://github.com/bleutner/big_grep.git 
+cd big_grep
+
+# Compile
+make
+
+## Run
+bin/big_grep -h
+```
+
+## Usage
 
 ```
 USAGE: big_grep [args] -p <patternfile> -i <inputfile>