More lines to describe the finidat sections

Add some comments to talk about what kind of land
tuning mode is being done for a section of finidat files.

bld/namelist_files/namelist_defaults_ctsm.xml

@@ -1326,7 +1326,7 @@ attributes from the config_cache.xml file (with keys converted to upper-case).
 <!--
      finidat files for CAM resolutions for being coupled to CAM
 -->
-<!-- clm5_0 -->
+<!-- clm5_0 and cam7.0 -->
 <finidat hgrid="0.9x1.25"  maxpft="17"  mask="gx1v7" use_cn=".false." use_cndv=".false." use_fates=".false."
          ic_ymd="19790101"  sim_year="1979" do_transient_pfts=".false."
          ic_tod="0" glc_nec="10" use_crop=".false." irrigate=".true."
@@ -1373,20 +1373,24 @@ attributes from the config_cache.xml file (with keys converted to upper-case).
 >lnd/clm2/initdata_map/clmi.BHIST.2000-01-01.0.9x1.25_gx1v7_simyr2000_c200728.nc
 </finidat>
 
+
+<!-- clm5_1 and cam7.0 -->
 <finidat hgrid="0.9x1.25"    maxpft="79"  mask="gx1v7" use_cn=".true." use_cndv=".false." use_fates=".false."
          ic_ymd="20000101" sim_year="2000" do_transient_pfts=".false."
          ic_tod="0" glc_nec="10" use_crop=".true." irrigate=".true."
          lnd_tuning_mode="clm5_1_cam7.0" use_init_interp=".true."
 >lnd/clm2/initdata_map/clmi.BHIST.2000-01-01.0.9x1.25_gx1v7_simyr2000_c200728.nc
 </finidat>
 
+<!-- clm6_0 and cam7.0 -->
 <finidat hgrid="0.9x1.25"    maxpft="79"  mask="gx1v7" use_cn=".true." use_cndv=".false." use_fates=".false."
          ic_ymd="20000101" sim_year="2000" do_transient_pfts=".false."
          ic_tod="0" glc_nec="10" use_crop=".true." irrigate=".true."
          lnd_tuning_mode="clm6_0_cam7.0" use_init_interp=".true."
 >lnd/clm2/initdata_map/clmi.BHIST.2000-01-01.0.9x1.25_gx1v7_simyr2000_c200728.nc
 </finidat>
 
+<!-- clm5_0 and cam7.0 -->
 <!-- 2003 -->
 <finidat hgrid="1.9x2.5"   maxpft="17"  mask="gx1v7" use_cn=".false." use_cndv=".false." use_fates=".false."
          ic_ymd="20030101"  sim_year="2003" do_transient_pfts=".false."
@@ -1533,7 +1537,7 @@ attributes from the config_cache.xml file (with keys converted to upper-case).
 <!--
      finidat files for CAM resolutions for being coupled to CAM
 -->
-<!-- clm5_0 -->
+<!-- clm5_0 and cam6.0-->
 <finidat hgrid="0.9x1.25"  maxpft="17"  mask="gx1v7" use_cn=".false." use_cndv=".false." use_fates=".false."
          ic_ymd="19790101"  sim_year="1979" do_transient_pfts=".false."
          ic_tod="0" glc_nec="10" use_crop=".false." irrigate=".true."
@@ -1611,6 +1615,7 @@ attributes from the config_cache.xml file (with keys converted to upper-case).
 >lnd/clm2/initdata_map/clmi.FHISTSp.2013-01-01.ne0CONUSne30x8_mt12_simyr2013_c200806.nc
 </finidat>
 <!-- Repeat above for clm5_1 -->
+<!-- clm5_1 and cam6.0-->
 <finidat hgrid="0.9x1.25"  maxpft="17"  mask="gx1v7" use_cn=".false." use_cndv=".false." use_fates=".false."
          ic_ymd="19790101"  sim_year="1979" do_transient_pfts=".false."
          ic_tod="0" glc_nec="10" use_crop=".false." irrigate=".true."
@@ -1674,6 +1679,7 @@ attributes from the config_cache.xml file (with keys converted to upper-case).
 >lnd/clm2/initdata_map/clmi.FHISTSp.2013-01-01.ne0CONUSne30x8_mt12_simyr2013_c200806.nc
 </finidat>
 <!-- Repeat above for clm6_0 -->
+<!-- clm6_0 and cam6.0-->
 <finidat hgrid="0.9x1.25"  maxpft="17"  mask="gx1v7" use_cn=".false." use_cndv=".false." use_fates=".false."
          ic_ymd="19790101"  sim_year="1979" do_transient_pfts=".false."
          ic_tod="0" glc_nec="10" use_crop=".false." irrigate=".true."