doc: update README.md

README.md

@@ -1,20 +1,21 @@
 # today
 
-Use **today** to review what you've done today! - In the future. Today is under construction now.
-
 ![Static Badge](https://img.shields.io/badge/C%2B%2B-17-blue) ![GitHub License](https://img.shields.io/github/license/Adamska1008/today)
 
+Today is a lightweight tool for tracking daily code commits, allowing developers to easily review the number of commits, lines changed and files modified each day.
+
 ## Usage
 
 ### Counting everyday commit
 
 By default **today** shows your commit today. Without specified `--author` every commit is counted.
 
 ```bash
-Use today to review what you have accomplished today!
+Use today to review what you've accomplished today!
 Usage:
   today [OPTION...]
 
+  -o, --offset arg     Offset from today (default: 0)
   -d, --directory arg  The working directory to be check (default: .)
   -h, --help           Print usage
 ```
@@ -42,6 +43,12 @@ Total: Commits 5, Lines Added 118, Lines Removed 9, Files Changed 6.
 +=========+======================================+======================+=============+===============+===============+
 ```
 
+Use `offset` options to check your commit yesterday or before yesterday.
+
+```sh
+today --offset=-1 # generally only negative number works, you can't predict the future
+```
+
 ## Setup
 
 ### Build from source