runtime(doc): use standard SGR format at :h xterm-true-color
By default, Vim uses the non-standard, but widely supported, legacy
xterm/Konsole format for setting "direct colors" with set setaf and
setbf escape codes, which use semicolons as separators.
The documentation for xterm-true-color mentions that, as an alternative,
users can set alternative sequences that use colons instead of
semicolons. This format, though, isn't standard and it is unclear how
widely supported it is; it was added by xterm patch 282 due to a
misinterpretation of the ISO 8613-6 (ITU T.416) standard, and was later
changed to the format suggested by this patch, which is the one
specified in the standard.
Today, looking at ncurses' [terminfo], it seems that all terminal
emulators use either the standard format (named "xterm+direct" in the
terminfo source) or the legacy format (named "xterm+indirect" in the
terminfo source).
Hence, I believe it makes sense to align the docs with reality.
If you're interested in the story of this escape sequence, I'd recommend
reading
<https://invisible-island.net/ncurses/ncurses.faq.html#xterm_16MegaColors>.
projects / thirdparty / vim.git / commit
