Small changes in doc file

zero or more keyword/value pairs may be appended :l

keyword = {evalue} or {nsub}

  {evalue} arg = {epair} or {evdwl} or {ecoul}

  {nsub} n = use {n}-th instance of a sub-style in a pair_style hybrid or hybrid/overlay command :pre

  {nsub} n = use the {n}-th instance of a sub-style in a pair_style hybrid or hybrid/overlay command :pre

:ule

[Examples:]

The specified {pstyle} must be a pair style used in your simulation

either by itself or as a sub-style in a "pair_style hybrid or

hybrid/overlay"_pair_hybrid.html command. If the sub-style is

used more than once, additional keyword {nsub} has to be specified in

order to choose a single instance.

used more than once, an additional keyword {nsub} has to be

specified in order to choose which instance of the sub-style will

be used by the compute.

NOTE: The {nsub} keyword should be used only if the sub-style occurs

multiple times. Its value must be an integer from 1 to M, where M is

the number of times the sub-style is listed in the "pair_style hybrid

or hybrid/overlay"_pair_hybrid.html" command. If the pair style is

used once, {nsub} must remain zero.

used only once, {nsub} must remain zero.

The {evalue} setting is optional.  All

pair styles tally a potential energy {epair} which may be broken into