V1.6.2 unstable

• Improvement: support markdown in note editor for mind map.
• Improvement: the performance of pasting long text to code editor.
• Improvement: add horizontal rule button to markdown toolbar for quick inserting.
• Improvement: use clearable text field for keyword input.
• Improvement: show image resolution in image viewer .
• Improvement: add Open menu item to workspace context menu.
• Improvement: add context menu for recent files list view.
• Fix: pressing backspace to delete letters, the input helper should not work when only 1 letter left.
• Update javafx to 21 and other dependencies includes plantuml, slf4j etc.
• Merged bug fixes from v1.5.6.