The `outline-indent.el' Emacs package provides a minor mode that enables code
folding and outlining based on indentation levels for various
indentation-based text files, such as YAML, Python, and other indented text
files.

In addition to code folding, `outline-indent.el' allows moving indented
subtrees up and down, promoting and demoting sections to adjust indentation
levels, customizing the ellipsis, and inserting a new line with the same
indentation level as the current line, among other features.

The `outline-indent.el' package utilizes the built-in outline-minor-mode,
which is maintained by the Emacs developers and is less likely to be
abandoned like *origami.el* or *yafolding.el*. Since `outline-indent.el' is
based on outline-minor-mode, it's also much much faster than origami.el and
yafolding.el.