Install libqscintilla2-doc by entering the following commands in the terminal:
sudo apt update sudo apt install libqscintilla2-doc
API documentation for QScintilla 2
QScintilla is a text editor for Qt4 and Qt5 with features especially useful when writing and debugging source code. These include support for syntax styling, error indicators, code completion, call tips and margins. . This package contains API documentation and usage examples for QScintilla 2 with both Qt4 and Qt5.