No gridlines on token attr plots+typo fix

Summary:
Gridlines can make negative signs and numbers harder to read. Removing them to ease readability.

Also relevant to aesthetics: D63039687

Differential Revision: D63062341

captum/attr/_core/llm_attr.py

@@ -88,6 +88,9 @@ def plot_token_attr(
 
         fig, ax = plt.subplots()
 
+        # Hide the grid
+        ax.grid(False)
+
         # Plot the heatmap
         data = token_attr.numpy()
 
@@ -119,7 +122,7 @@ def plot_token_attr(
 
         # Create colorbar
         cbar = fig.colorbar(im, ax=ax)  # type: ignore
-        cbar.ax.set_ylabel("Token Attribuiton", rotation=-90, va="bottom")
+        cbar.ax.set_ylabel("Token Attribution", rotation=-90, va="bottom")
 
         # Show all ticks and label them with the respective list entries.
         shortened_tokens = [
@@ -204,7 +207,7 @@ def plot_seq_attr(
             color="#d0365b",
         )
 
-        ax.set_ylabel("Sequence Attribuiton", rotation=90, va="bottom")
+        ax.set_ylabel("Sequence Attribution", rotation=90, va="bottom")
 
         if show:
             plt.show()