feat(native): enable debug-option by default in debug-build. (#12470)

Author: supervacuus

docs/platforms/native/common/configuration/options.mdx

@@ -31,7 +31,7 @@ Allows you to specify a path to the local event- and crash-database of the Nativ
 
 <ConfigKey name="debug">
 
-Turns debug mode on or off. If debug is enabled SDK will attempt to print out useful debugging information if something goes wrong with sending the event. The default is always `false`. It's generally not recommended to turn it on in production, though turning `debug` mode on will not cause any safety concerns.
+Turns debug mode on or off. If `debug` is enabled, the SDK will attempt to print out useful debugging information if something goes wrong. If you run a debug-build (`NDEBUG` isn't defined), it will default to `true`; otherwise, the default is always `false`. You can provide a `SENTRY_DEBUG` environment variable with either `"0"` or `"1"` for "off" and "on" respectively, which will override the defaults. It's generally not recommended to turn it on in production, though turning `debug` mode on will not cause any safety concerns. You can limit the output by setting `logger_level` to an appropriate level for your production use case.
 
 </ConfigKey>