docs: update README.md with example usage

README.md

@@ -10,4 +10,23 @@ into well-structured data.
 
 ## Usage
 
-TODO: show usage
+```go
+package main
+
+import (   
+    "log"
+    "github.com/bradleybonitatibus/frostparse"
+)
+
+func main() {
+    p := frostparse.New(
+        frostparse.WithLogFile("C:\\Program Files (x86)\\World of Warcraft 3.3.5a\\Logs\\WoWCombatLog"),
+    )
+    _data, err := p.Parse()
+    if err != nil {
+        log.Fatal("failed to parse combatlog: ", err)
+    }
+    // handle []*frostparse.CombatLogRecord how you please
+}
+
+```