fix(textarea): clamp undo/redo cursor after oversized delete_str (#9)

Cargo.toml

@@ -3,7 +3,7 @@ name = "tui-textarea-2"
 homepage = "https://github.com/srothgan/tui-textarea#readme"
 repository = "https://github.com/srothgan/tui-textarea"
 documentation = "https://docs.rs/tui-textarea-2/latest/tui_textarea/"
-version = "0.9.0"
+version = "0.9.1"
 edition = "2021"
 rust-version = "1.56.1" # for `tui` crate support
 authors = ["Simon Peter Rothgang <simonrothgang@icloud.com>", "rhysd <lin90162@yahoo.co.jp>"]