feat: configurable indent marker level

[and-rs]

The current marker starts after the 2nd node, and this PR modifies the indent function to make the indent marker start from node 0 or 1, also making it configurable. Just like this:

I tried covering some edge cases due to the different combinations from:

  local indent_size = config.indent_size
  local padding = config.padding
  local marker_start_level = config.marker_start_level
  local level = node.level
  local with_markers = config.with_markers
  local with_expanders = config.with_expanders == nil and file_nesting.is_enabled()
    or config.with_expanders

Most of the logic was changed, of course I am open to improving the quality of the code and implement perhaps more edge cases or anything else. Thank you

Edit: There are still issues with the conditionals, and honestly I am having a hard time putting it all together, this is definitely not ready to be merged

[and-rs]

Alright, I refactored the code again, and this should handle most cases for indentation options. Perhaps other people trying it would be great.

[sand4rt]

It works great on my machine. Got the same behaviour as the screenshots in the PR description.

Not a showstopper IMO, but it would be nice if marker_start_level = 0 + hide_root_node = false:

would behave same as with marker_start_level = 0 + hide_root_node = true:

[sand4rt]

found something:

the indent_size and the marker_start_level looks off when using: ["<"] = "prev_source" [">"] = "next_source".

[and-rs]

Mmm yea I just saw that too, I guess I never use other sources, that's a really weird extra padding. Will check that out tomorrow or Tuesday. Thank you for testing it out

[sand4rt]

Did you make any more progress? Maybe we should merge it as is?