Conflicts with Prettier

We recommend trainees use Prettier, and it's included in [our extension pack](https://github.com/CodeYourFuture/cyf-extension-pack). However, when it's used with this ESLint configuration, there are various conflicts that cause a bunch of errors to appear.

For example, the default in Prettier is to indent with two spaces, rather than tabs (although this is [configurable](https://prettier.io/docs/en/options.html#tab-width) with `useTabs: true` in a `.prettierrc` or one of [the other options](https://prettier.io/docs/en/configuration.html)).

In general, Prettier wants to be doing all of the style stuff and leave linters to finding possible errors (see https://prettier.io/docs/en/comparison.html). There's an [ESLint config](https://github.com/prettier/eslint-config-prettier) available that just turns off a bunch of rules, including most set here (everything except `no-unused-vars` ,`no-var`), to avoid conflicts.

One of the conflicts can be avoided with a tweak to this configuration:

```json
"quotes": ["error", "double", { "avoidEscape": true, "allowTemplateLiterals": false }]
```

but `indent` and `operator-linebreak` will still conflict:

### Rule summary:

- `arrow-parens`: no conflict, can explicitly set `arrowParens: "always"` in `.prettierrc`
- `brace-style`: no conflict
- `comma-dangle`: no conflict, can explicitly set `trailingComma: "es5"` in `.prettierrc`
- `curly`: no conflict with the default `"all"` config per https://github.com/prettier/eslint-config-prettier#curly
- `indent`: **conflict**, we can ask Prettier to use tabs with `useTabs: true` in `.prettierrc` but it will still use spaces for alignment, ESLint and Prettier take fundamentally different approaches here (see e.g. https://github.com/eslint/eslint/issues/10930#issuecomment-427690631)
- `linebreak-style`: no conflict, can explicitly set `endOfLine: "lf"` in `.prettierrc`
- `no-trailing-spaces`: no conflict
- `no-unused-vars`: _not a style rule_
- `no-var`: _not a style rule_
- `object-curly-spacing`: no conflict, can explicitly set `bracketSpacing: true` in `.prettierrc`
- `operator-linebreak`: **conflict** Prettier will put some operators at the end of the line (see discussion at https://github.com/prettier/prettier/issues/3806)
- `quotes`: **needs update** to these rules, to `avoidEscape` and not `allowTemplateLiterals`, can explicitly set `singleQuote: false` in `.prettierrc`
- `semi`: no conflict, can explicitly set `semi: true` in `.prettierrc`

An explicit `.prettierrc` for all of these changes would look like:

```yaml
arrowParens: "always"
bracketSpacing: true
endOfLine: "lf"
semi: true
singleQuote: false
trailingComma: "es5"
useTabs: true # non-default
```

For folks using this style with Prettier, do we recommend they override the two conflicting rules?

```json
{
"extends": [
"@codeyourfuture/standard"
],
"rules": {
"indent": "off",
"operator-linebreak": "off"
}
}
```

Or remove them from this styling entirely?

Start by reviewing the current ESLint configuration and the listed Prettier rules, then compare the proposed `.prettierrc` settings and `eslint-config-prettier` guidance. Resolve whether `indent` and `operator-linebreak` should be overridden or removed, update the configuration accordingly, and verify that the documented Prettier setup no longer reports conflicts.

Written by the indexing model from the issue text.