add changelog, update readme

CHANGELOG.md

@@ -0,0 +1,7 @@
+# CHANGELOG
+
+## [v0.0.1] - 2022-09-20
+
+- Add semver version `v0.0.1` (see semver.org)
+- Add `NewWithOptions(url string, opts ...Option)` for custom client settings
+- Rollback `go.mod` package name to `github.com/badkaktus/gorocket`

README.md

@@ -31,6 +31,16 @@ if err != nil {
 fmt.Printf("I'm %s", lg.Data.Me.Username)
 ```
 
+or 
+
+```go
+client := gorocket.NewWithOptions("https://your-rocket-chat.com", 
+    gorocket.WithUserID("my-user-id"),
+    gorocket.WithToken("my-bot-token"),
+    gorocket.WithTimeout(1 * time.Second),
+)
+```
+
 ## Manage user
 ```go
 str := gorocket.NewUser{