Fix a space error.

src/groups/group_action.jl

@@ -116,7 +116,7 @@ where element `a` is acting on `p`, with respect to the group element.
 
 Let ``\mathcal G`` be the group acting on manifold ``\mathcal M`` by the action `A`.
 The action is of element ``g ∈ \mathcal G`` on a point ``p ∈ \mathcal M``.
-The differential transforms vector `X` from the tangent space at `a ∈ \mathcal G`, 
+The differential transforms vector `X` from the tangent space at `a ∈ \mathcal G`,
 ``X ∈ T_a \mathcal G`` into a tangent space of the manifold ``\mathcal M``.
 When action on element `p` is written as ``\mathrm{d}τ^p``, with the specified left or right
 convention, the differential transforms vectors