[docs] fix broken SynapseML link (#4712)
[docs] fix broken SynapseML link (#4712)

* [docs] fix broken SynapseML link

* just remove link
henry0312/LightGBM,microsoft/LightGBM,microsoft/LightGBM,microsoft/LightGBM,microsoft/LightGBM,henry0312/LightGBM,henry0312/LightGBM,henry0312/LightGBM,microsoft/LightGBM,henry0312/LightGBM