Fix Doxygen in global_cycle

[GeorgeGayno-NOAA]

DESCRIPTION OF CHANGES:

• Add definitions for two arguments in the read_data routine.
• Add checks for missing optional argument LSOIL_INCR in read_data.
• Update the pull request template to always require a branch be compiled with
  Doxygen before merging.

TESTS CONDUCTED:

If there are changes to the build or source code, the tests below must be conducted. Contact a repository manager if you need assistance.

• Compile branch on all Tier 1 machines using Intel (Orion, Jet, Hera, Hercules and WCOSS2). Done using 88b38a8.
• Compile branch on Hera using GNU. Done using 88b38a8.
• Compile branch in 'Debug' mode on WCOSS2. Done on Cactus using 88b38a8.
• Run unit tests locally on any Tier 1 machine. Done on Cactus using 88b38a8. All tests passed.
• Run global_cycle consistency tests locally on all Tier 1 machines. Done using 88b38a8. All tests passed as expected.

Describe any additional tests performed.

• On Hera, the repository (at 88b38a8) was built with Doxygen with no errors. There were no warnings associated with the global_cycle code.

DEPENDENCIES:

None.

DOCUMENTATION:

Minor fixes to the Doxygen.

ISSUE:

Fixes #1025.

[yuanxue2870]

Looks good to me! Thanks for the fix.