Added headers to subroutines that were missing them

src/encounter/encounter_io.f90

@@ -33,6 +33,9 @@ module subroutine encounter_io_write_frame(iu, t, id1, id2, Gmass1, Gmass2, radi
    end subroutine
 
    module subroutine encounter_io_write_list(self, pl, encbody, param)
+      !! author: David A. Minton
+      !!
+      !! Write the encounters to the output encounter binary files
       implicit none
       ! Arguments
       class(encounter_list),  intent(in) :: self    !! Swiftest encounter list object

src/helio/helio_drift.f90

@@ -77,6 +77,9 @@ end subroutine helio_drift_tp
 
 
    pure elemental subroutine helio_drift_linear_one(xhx, xhy, xhz, ptx, pty, ptz, dt)
+      !! author: David A. Minton
+      !!
+      !! Calculate the linear drift for a single body
       implicit none
       real(DP), intent(inout) :: xhx, xhy, xhz
       real(DP), intent(in) :: ptx, pty, ptz, dt
@@ -90,6 +93,9 @@ end subroutine helio_drift_linear_one
 
 
    subroutine helio_drift_linear_all(xh, pt, dt, n, lmask)
+      !! author: David A. Minton
+      !!
+      !! Loop through all the bodies and calculate the linear drift
       implicit none
       ! Arguments
       real(DP), dimension(:,:), intent(inout) :: xh

src/symba/symba_io.f90

@@ -158,6 +158,9 @@ end subroutine symba_io_param_writer
 
 
    module subroutine symba_io_write_discard(self, param)
+      !! author: David A. Minton
+      !!
+      !! Write the metadata of the discarded body to the output file 
       implicit none
       class(symba_nbody_system),  intent(inout) :: self  !! SyMBA nbody system object
       class(swiftest_parameters), intent(inout) :: param !! Current run configuration parameters