Bug#992793: isort manpages

[Rebecca N. Palmer]

Control: tags -1 patch

The fix992793 branch in Salsa updates this manpage, and also adds one 
for isort-identify-imports.

It has the lintian warning
groff-message troff:<standard input>:23: warning [p 1, 2.8i]: cannot 
adjust line [usr/share/man/man1/isort.1.gz:1]
which probably refers to the long line without spaces

{GRID,VERTICAL,HANGING_INDENT,...,0,1,2,3,4,5,6,7,8,9,10,11}

I don't know whether this notation allows adding spaces to remove this 
warning.