Update documentation for variables in CALGUST.f and CALHEL.f (#630)

* Correct DEPTH param in CALHEL

* add def for LPBL and ZPBL

* reorder variables in header

---------

Co-authored-by: gspetro <gillian.s.petro@gmail.com>

sorc/ncep_post.fd/CALGUST.f

@@ -3,8 +3,10 @@
 !
 !> This routine computes surface wind gust by mixing
 !> down momentum from the level at the height of the PBL.
-!>     
-!> @param[out] GUST Speed of the maximum surface wind gust.
+!> 
+!> @param[in] LPBL Model level that is closest to the planetary boundary layer height.
+!> @param[in] ZPBL Height of the planetary boundary layer.
+!> @param[inout] GUST Speed of the maximum surface wind gust.
 !>
 !> ### Program history log:
 !> Date | Programmer | Comments

sorc/ncep_post.fd/CALHEL.f

@@ -13,7 +13,7 @@
 !> 'non-classic' hodographs (such as Northwest-flow events) and do as well or 
 !> better than the old method in more classic situations.
 !>     
-!> @param[in] DPTH Depth in meters over whcih helicity should be computed; allows one to distinguish 0-3 km and 0-1 km values.
+!> @param[in] DEPTH Depth in meters over whcih helicity should be computed; allows one to distinguish 0-3 km and 0-1 km values.
 !> @param[out] UST Estimated U Component (m/s) Of Storm motion.
 !> @param[out] VST Estimated V Component (m/s) Of Storm motion.
 !> @param[out] HELI Storm-relative heliciry (m**2/s**2).