add installing FreeTDS steps to README

README.md

@@ -1,5 +1,21 @@
 # Usage
-## at the target app, not this Orbit module(Rails Engine)
+## install FreeTDS for school server in advance
+```shell
+# install steps for Ubuntu
+$ sudo apt-get install wget
+$ sudo apt-get install build-essential
+$ sudo apt-get install libc6-dev
+
+$ sudo wget http://www.freetds.org/files/stable/freetds-1.1.6.tar.gz
+$ sudo tar -xzf freetds-1.1.6.tar.gz
+$ sudo cd freetds-1.1.6
+$ sudo ./configure --prefix=/usr/local --with-tdsver=7.3
+$ sudo make
+$ sudo make install
+```
+More infomation please visit [TinyTDS.](https://github.com/rails-sqlserver/tiny_tds)
+
+## do the steps below at the target app directory, not this Orbit module directory(Rails Engine)
 * create project\_root/config/initializers/ntnu\_sybase\_config.rb with following content:
 
 ```ruby