lineheight is not documented for insert_textbox

[Andreasox]

Description of the bug

e.g. in https://pymupdf.readthedocs.io/en/latest/shape.html#Shape.insert_textbox
And the name lineheight is confusing in my understanding as it changes the line spacing.

How to reproduce the bug

see above

PyMuPDF version

1.23.8

Operating system

MacOS

Python version

3.9

[JorjMcKie]

And the name lineheight is confusing in my understanding as it changes the line spacing.

A matter of personal taste I think. Line spacing isn't more correct.
The "natural" line height of a font (my own unofficial term) is the value lh = font.ascender - font.descender. If using the default of lineheight (1.0), a value of lh * fontsize is used. Outputting text that way, leads to zero inter-line overlaps.
Many PDF creators save space on the page by using a smaller value, like lh * fontsize * 0.8. Searching for or extracting text in such a situation delivers bboxes that overlap text in neighboring lines. One can prevent this by setting a global variable fitz.TOOLS.set_small_glyph_heights(True)before extractions and searches.

[julian-smith-artifex-com]

Fixed in 1.23.9.