Add MQ2 Gas sensor & tweak DHT config to avoid editing source when PI…

[diepeterpan]

Description:

Add MQ2 Combustible Gas sensor & tweak DHT config to avoid editing source when PIN is different

This MQ-2 Methane Gas Sensor module detects a wide range of potentially dangerous gases, with an onboard potentiometer for adjusting sensitivity.

Checklist:

• The pull request is done against the latest development branch
• Only one feature/fix was added per PR and the code change compiles without warnings
• I accept the DCO.

[1technophile]

Thanks for the PR.
For Lint, if you right-click into the code in VSC, you should have a "Format document" option. This will format the code directly according to the expectations.

[diepeterpan]

Thanks for the PR. For Lint, if you right-click into the code in VSC, you should have a "Format document" option. This will format the code directly according to the expectations.

Thanks, was not sure whether it will work, will make a note of it.