feat: adapted to the latest parser

[blindFS]

This PR adapted the formatter to be compatible with the latest tree-sitter-nu parser.

It contains a hack solution for the inconsistent behavior of assignment that should be fixed in the future.

;; FIXME: temp workaround for the whitespace issue
[
  ":"
  ";"
  "do"
  "if"
  "match"
  "try"
  "while"
] @append_space

[
  "="
  (match_guard)
] @prepend_space

(assignment
  opr: _
  rhs: (pipeline
    (pipe_element
      (val_string
        (raw_string_begin)
      )
    )
  ) @prepend_space
)

(
  "="
  .
  (pipeline
    (pipe_element
      (val_string
        (raw_string_begin)
      )
    )
  ) @prepend_space
)