Update README.md

Author: joonas-yoon

README.md

@@ -1,5 +1,42 @@
-# BOJ Saver
+# BOJ source saver
 
-## Chrome WebDriver
+Save your ACCEPTED codes on [BOJ](https://www.acmicpc.net)
 
-https://sites.google.com/a/chromium.org/chromedriver/downloads
+## Requirements
+
+- Chrome WebDriver
+- Python 3
+- pip
+
+### Chrome WebDriver
+
+Download `chromedriver.exe` from https://sites.google.com/a/chromium.org/chromedriver/downloads
+
+and place it in project directory.
+
+## Set up
+
+(optional) create virutal environment for python if you need
+
+Install python packages:
+```
+$ pip install -r requirements.txt
+```
+
+## How to use
+
+Run a command as following:
+```
+$ python main.py
+```
+
+Chrome starts, and it wait for log in website(BOJ).
+
+When you logged in BOJ, this script will get your latest accepted sources for each problems.
+
+Sources are saved in `~/sources` directory with `{problem_id}.{language_extention}`  (e.g. `1000.py`)
+
+
+## Terms of Use
+
+We do not take disadvantage by running this program. **You are responsible for your own actions**