Describe position POS (interactively, point) and the char after POS.
POS is taken to be in BUFFER, or the current buffer if BUFFER is nil.
The information is displayed in buffer `*Help*'.
The position information includes POS; the total size of BUFFER; the
region limits, if narrowed; the column number; and the horizontal
scroll amount, if the buffer is horizontally scrolled.
The character information includes the character code; charset and
code points in it; syntax; category; how the character is encoded in
BUFFER and in BUFFER's file; character composition information (if
relevant); the font and font glyphs used to display the character;
the character's canonical name and other properties defined by the
Unicode Data Base; and widgets, buttons, overlays, and text properties
relevant to POS.
(fn POS &optional BUFFER)