Use unknown for Catch Variables

If `unknown` is new to you, read: example:unknown-and-never Since TypeScript 4.0, you have been able to change the type of the variable in a catch statement from the default of `any` to `unknown` by manually assigning the type: 

try {
  // @ts-ignore
  iWillCrash();
} catch (err) {
  // This implicitly means you _have_ to declare
  // what the type is before you can write code
  // against `err`:
  console.log(err.message);

  // For example, we have to verify it is an
  // error before using it as one.
  if (err instanceof Error) {
    console.log(err.message);
  }
}

// Also: example:unknown-in-catch
// By using the option `useUnknownInCatchVariables`, you can have the compiler default to `unknown` instead of `any`. Effectively forcing all usage of that variable to be confirmed by the type system before usage. You can opt-out on one-off catch statements by assigning the variable to `any`. 
try {
  // @ts-ignore
  iWillCrash();
} catch (err: any) {
  // In which case, you can treat it
  // however you would like.
  console.log(err.message);
}