Fix formatting in GIBUU sample table by keeping empty cells in the middle of the table

Fix formatting in GIBUU sample table by keeping empty cells in the middle of the table

Author: PrabhjotSingh247

sbn/sbnprod_wiki/sample.md

@@ -67,8 +67,8 @@ Monte Carlo official SBN Production Samples
 | Sample Description | production push | release version | # Events | SAM Database |
 | --- | --- | --- | --- | --- |
 | BNB + Cosmics - gen1 | SBND2026A | v10_06_00_09 | ~200k | SBND only |
-| reco1 | mc_SBND2026A_gen1_prodgenie_corsika_proton_rockbox_sbnd_GIBUU_CV_v10_06_00_09_reco1_sbnd |
-| flatcaf | mc_SBND2026A_gen1_prodgenie_corsika_proton_rockbox_sbnd_GIBUU_CV_v10_06_00_09_flatcaf_sbnd |
+| reco1 | | | | mc_SBND2026A_gen1_prodgenie_corsika_proton_rockbox_sbnd_GIBUU_CV_v10_06_00_09_reco1_sbnd |
+| flatcaf | | | | mc_SBND2026A_gen1_prodgenie_corsika_proton_rockbox_sbnd_GIBUU_CV_v10_06_00_09_flatcaf_sbnd |
 
 #### Fall Production 2025 (gen2) - Syst Variations
 | Sample Description | production push | release version | # Events | SAM Database |