comment out

[ignatandrei]

Is your feature request related to a problem? Please describe.
Comment out lines of code

Describe the solution you'd like
text_commentout like in
https://github.com/MediaTek-Labs/BlocklyDuino-for-LinkIt/blob/43693233bc56312dfae7a7db5f93c5870b832206/blockly/generators/arduino/text.js#L37

Describe alternatives you've considered
comment