Linter: flag to avoid emitting warnings

[Vivalldi]

Some teams prefer certain rules to warn rather than error. These warnings are extremely useful in the editor to prompt developers to double check their work. Warnings in the biome lint output can become overbearing at times when attempting to find diagnostics that are set to error. An optional flag to hide warnings from the output would help locate errors more quickly.

• --hide-warnings
• --skip-warnings (might cause confusion with --skip-errors)
• --omit-warnings
• --errors-only

[ematipico]

I like the proposal, I think it makes sense.

About the naming, since we added --log-level, we could stick to that naming convention and use --diagnostic-level, and the order will be as follows (from lowest to highest):

• Fatal
• Panic
• Info
• Warning
• Error

This means that if you pass --diagnostic-level=info you will see only info, warnings and errors. If you pass --diagnostic-level=error you will see only errors. What do you think?

[Vivalldi]

That name makes perfect sense! Not sure I understand why fatal & panic are lowest instead of highest.

[ematipico]

Yeah you're right, they should be the hightest