DOC: Add accessor table entry

Author: rluce

web/pandas/community/ecosystem.md

@@ -553,6 +553,7 @@ authors to coordinate on the namespace.
   | [composeml](https://github.com/alteryx/compose)                      | `slice`    | `DataFrame`           |
   | [datatest](https://datatest.readthedocs.io/en/stable/)               | `validate` | `Series`, `DataFrame` |
   | [composeml](https://github.com/alteryx/compose)                      | `slice`    | `DataFrame`           |
+  | [gurobipy-pandas](https://github.com/Gurobi/gurobipy-pandas)         | `gppd`     | `Series`, 'DataFrame` |
   | [staircase](https://www.staircase.dev/)                              | `sc`       | `Series`, `DataFrame` |
   | [woodwork](https://github.com/alteryx/woodwork)                      | `slice`    | `Series`, `DataFrame` |