Convert selected text by your custom script.

1. Install selection-converter
2. Open Command Palette, and type Convert Selected Text
3. A file named .vscode/selection-convert.js will be created and opened automatically.
4. Write your custom converting script.
5. Select the text which you want to convert.
6. Redo step 2, this time your custom converters shoud show up.
7. Pick the one your want to run, and selected text will be replaced.