fix link in gate notebook

Author: SvenKlaassen

doc/examples/py_double_ml_gate.ipynb

@@ -33,7 +33,7 @@
     "\n",
     "We define a data generating process to create synthetic data to compare the estimates to the true effect. The data generating process is based on the Monte Carlo simulation from [Oprescu et al. (2019)](http://proceedings.mlr.press/v97/oprescu19a.html).\n",
     "\n",
-    "The documentation of the data generating process can be found [here](https://docs.doubleml.org/dev/api/api.html#dataset-generators). In this example the true effect depends only the first covariate $X_0$ and takes the following form\n",
+    "The documentation of the data generating process can be found [here](https://docs.doubleml.org/dev/api/datasets.html#dataset-generators). In this example the true effect depends only the first covariate $X_0$ and takes the following form\n",
     "\n",
     "$$\n",
     "\\theta_0(X) = \\exp(2X_0) + 3\\sin(4X_0).\n",