Allow toggling display of error underlining and red circles in code

[adamkpickering]

As code is written helix underlines errors in the code. One example is variables that are not used. However, the code that uses these variables is not yet written! Of course, once the code is written the errors disappear. Here is an example:

errors is not yet used, but it is going to be. Same thing with error.

Sometimes I find the underlining and red circles distracting. I propose adding a command (or maybe even key sequence?) that causes errors to temporarily not be displayed so that the user can focus on writing code. Once the user is done writing the code, they can re-enable displaying errors.