add typo fix from #2472

Author: rohan-bansal

gtsam/navigation/doc/ImuFactor.ipynb

@@ -29,7 +29,7 @@
         "Instead of connecting five variables (`Pose_i`, `Vel_i`, `Pose_j`, `Vel_j`, `Bias_i`), the `ImuFactor2` connects three:\n",
         "\n",
         "1. `NavState` at time $i$ (`NavState` combines pose and velocity)\n",
-        "2. `NavState` at time $j`\n",
+        "2. `NavState` at time $j$\n",
         "3. IMU Bias at time $i$ (`imuBias::ConstantBias`)\n",
         "\n",
         "### Modeling Bias\n",
@@ -48,7 +48,13 @@
         ]
       },
       "source": [
-        "GTSAM Copyright 2010-2022, Georgia Tech Research Corporation,\nAtlanta, Georgia 30332-0415\nAll Rights Reserved\n\nAuthors: Frank Dellaert, et al. (see THANKS for the full author list)\n\nSee LICENSE for the license information"
+        "GTSAM Copyright 2010-2022, Georgia Tech Research Corporation,\n",
+        "Atlanta, Georgia 30332-0415\n",
+        "All Rights Reserved\n",
+        "\n",
+        "Authors: Frank Dellaert, et al. (see THANKS for the full author list)\n",
+        "\n",
+        "See LICENSE for the license information"
       ]
     },
     {
@@ -330,4 +336,4 @@
   },
   "nbformat": 4,
   "nbformat_minor": 2
-}
+}