fixing README.md

Author: yeger00

README.md

@@ -1,11 +1,13 @@
 # graph-diff
 Utilities to view diff between graphs
 
-# Getting starget
+# Getting started
 
 ## Install prerequisites 
-1. graph-easy
-
+Debian / Ubuntu:
+```
+sudo apt-get install libgraph-easy-perl
+```
 ## Install
 ```
 git clone https://github.com/yeger00/graph-diff
@@ -20,11 +22,20 @@ python -m graphdiff samples/before.dot samples/after.dot > ./diff.dot
 cat ./diff.dot | ./diff-graph-color
 ```
 
-# git-diff
-![Alt text](images/git-log-example.gif?raw=true "Title")
+# git-graph-diff-tool
+It is possible to use graph-diff with git, with `git-graph-diff-tool` provided in this library. An usage example:
+![](images/git-log-example.gif?raw=true "git-graph-diff-tool example")
 
+## Install
+For every repository you would like to install you need to add to .gitattributes file a rules to know how to handle .dot files. For example:
+```
+echo "*.dot diff=graph_diff" >> .gitattributes
+```
+Then, configure the difftool to be the `git-graph-diff-tool`. For example:
 ```
 git config diff.graph_diff.command /path/to/git-graph-diff-tool
-*.dot diff=graph_diff
-git log -p --ext-diff classes.dot
+```
+Then, you can use git as usual, while adding `--ext-diff` flag to enable external difftools.
+```
+git log -p --ext-diff
 ```