Titles in links don't convert properly

Links aren't converted properly if title is provided.

How to reproduce

final linkWithTitle = html2md.convert("<a href="https://example.com" title="Example title">Example content</a>");

What is returned:

[Example content](https://example.comExample title)

What is expected (verifiable via https://domchristie.github.io/turndown/):

[Example content](https://example.com "Example title")

Environment

flutter doctor -v

``` ➜ flutter doctor -v [✓] Flutter (Channel beta, 2.0.1, on macOS 11.0.1 20B50 darwin-x64, locale en-GB) • Flutter version 2.0.1 at /Users/kubcio/.flutter • Framework revision c5a4b4029c (12 days ago), 2021-03-04 09:47:48 -0800 • Engine revision 40441def69 • Dart version 2.12.0 [✓] Android toolchain - develop for Android devices (Android SDK version 30.0.2) • Android SDK at /Users/kubcio/Library/Android/sdk • Platform android-30, build-tools 30.0.2 • Java binary at: /Applications/Android Studio.app/Contents/jre/jdk/Contents/Home/bin/java • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6915495) • All Android licenses accepted. [✓] Xcode - develop for iOS and macOS • Xcode at /Applications/Xcode.app/Contents/Developer • Xcode 12.4, Build version 12D4e • CocoaPods version 1.10.1 [✓] Chrome - develop for the web • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome [✓] Android Studio (version 4.1) • Android Studio at /Applications/Android Studio.app/Contents • Flutter plugin can be installed from: 🔨 https://plugins.jetbrains.com/plugin/9212-flutter • Dart plugin can be installed from: 🔨 https://plugins.jetbrains.com/plugin/6351-dart • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6915495) [✓] IntelliJ IDEA Ultimate Edition (version 2020.3.2) • IntelliJ at /Applications/IntelliJ IDEA.app • Flutter plugin version 54.0.3 • Dart plugin version 203.7759 [✓] VS Code (version 1.54.3) • VS Code at /Applications/Visual Studio Code.app/Contents • Flutter extension version 3.20.0 [✓] Connected device (3 available) • iPhone 11 (mobile) • 5081BDDF-BBB7-4110-A773-2B2F2AB9A700 • ios • com.apple.CoreSimulator.SimRuntime.iOS-14-4 (simulator) • macOS (desktop) • macos • darwin-x64 • macOS 11.0.1 20B50 darwin-x64 • Chrome (web) • chrome • web-javascript • Google Chrome 89.0.4389.82 • No issues found! ```

jarontai / html2md