Reconsider 2 vs 4 space indentation about ktfmt

[cgrushko]

@eyalgu, give it a try - ktfmt --dropbox-style Filename.kt

[eyalgu]

For reference, the Kotlin formatting guideline, which is why everyone does 4 (including all other popular formatters) https://kotlinlang.org/docs/reference/coding-conventions.html#formatting

[eyalgu]

Actually, indent size seems to be one of the only configurable values in ktlint (probably because it's so important to have that consistent). I know (and love) your attitude against configuration, but this could be good candidate for an exception

For completeness, the other 2 config values ktlint calls out are:

1. max line length
2. insert new line at end of file

I feel way less strongly about these 2, though I would also appreciate a way to bump the line length like in ktlint.