Cleaned up docs for pair_mores, a missing :pre ruined formatting.

doc/src/pair_morse.txt

@@ -26,7 +26,7 @@ args = list of arguments for a particular style :ul
  {morse/smooth/linear} args = cutoff
    cutoff = global cutoff for Morse interactions (distance units)
  {morse/soft} args = n lf cutoff
-   n = soft-core parameter
+   n       = soft-core parameter
    lf      = transformation range is lf < lambda < 1
    cutoff  = global cutoff for Morse interactions (distance units)
 :pre
@@ -36,7 +36,7 @@ args = list of arguments for a particular style :ul
 pair_style morse 2.5
 pair_style morse/smooth/linear 2.5
 pair_coeff * * 100.0 2.0 1.5
-pair_coeff 1 1 100.0 2.0 1.5 3.0
+pair_coeff 1 1 100.0 2.0 1.5 3.0 :pre
 
 pair_style morse/soft 4 0.9 10.0
 pair_coeff * * 100.0 2.0 1.5 1.0