fix math formatting

Author: drbenvincent

docs/source/notebooks/event_study_pymc.ipynb

@@ -25,11 +25,13 @@
     "An event study analyzes panel data where some units receive treatment at a specific time. Unlike standard difference-in-differences which estimates a single average treatment effect, event studies estimate **separate coefficients for each time period relative to treatment**.\n",
     "\n",
     "The key concept is **event time** (or relative time):\n",
+    "\n",
     "$$E_{it} = t - G_i$$\n",
     "\n",
     "where $t$ is the calendar time and $G_i$ is the treatment time for unit $i$.\n",
     "\n",
     "The model estimates:\n",
+    "\n",
     "$$Y_{it} = \\alpha_i + \\lambda_t + \\sum_{k \\neq k_0} \\beta_k \\cdot \\mathbf{1}\\{E_{it} = k\\} + \\varepsilon_{it}$$\n",
     "\n",
     "where:\n",