isspace.3: Fix list block

[ziaee]

lib/libc/locale/isspace.3

54

These were previously ordered according to ASCII?

55

57

These aren't sentences, so I prefer to use nothing (and lowercase first character, this is how they did it in the beginning); you could use a comma, but you certainly shouldn't use a period.

[jlduran]

Address suggestions:

• Sort entries according to ascii(7)
• Use the "standard" "indent" width
• Lowercase the items

Also:

• Remove the reference to a historical 386BSD (it no longer applies)

[jlduran]

Note to self: isdigit(3) also needs a little fix.