fix(field_theory/galois): update docstring (#13188)

src/field_theory/galois.lean

@@ -24,11 +24,12 @@ In this file we define Galois extensions as extensions which are both separable
 
 ## Main results
 
-- `fixing_subgroup_of_fixed_field` : If `E/F` is finite dimensional (but not necessarily Galois)
-  then `fixing_subgroup (fixed_field H) = H`
-- `fixed_field_of_fixing_subgroup`: If `E/F` is finite dimensional and Galois
+- `intermediate_field.fixing_subgroup_fixed_field` : If `E/F` is finite dimensional (but not
+  necessarily Galois) then `fixing_subgroup (fixed_field H) = H`
+- `intermediate_field.fixed_field_fixing_subgroup`: If `E/F` is finite dimensional and Galois
   then `fixed_field (fixing_subgroup K) = K`
-Together, these two result prove the Galois correspondence
+
+Together, these two results prove the Galois correspondence.
 
 - `is_galois.tfae` : Equivalent characterizations of a Galois extension of finite degree
 -/