📝 Add RequiredBridges in doc

Author: blegat

docs/src/apireference.md

@@ -19,8 +19,8 @@ AbstractConstraintAttribute
 
 Attributes can be set in different ways:
 
-* it is either set when the model is created like [`SolverName`](@ref) and
-  [`RawSolver`](@ref),
+* it is either set when the model is created like [`SolverName`](@ref),
+  [`RequiredBridges`](@ref) and [`RawSolver`](@ref),
 * or explicitly when the model is copied like [`ObjectiveSense`](@ref),
 * or implicitly, e.g., [`NumberOfVariables`](@ref) is implicitly set by
   [`add_variable`](@ref) and [`ConstraintFunction`](@ref) is implicitly set by
@@ -88,6 +88,7 @@ List of attributes optimizers attributes
 
 ```@docs
 SolverName
+RequiredBridges
 ```
 
 List of attributes useful for optimizers