minor symfony#15316 CI: Add new rule for DOCtor-RST (OskarStark)

This PR was merged into the 4.4 branch.

Discussion
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CI: Add new rule for DOCtor-RST

Follows symfony#15313

Commits
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f6826fa CI: Add new rule for DOCtor-RST

Author: OskarStark

.doctor-rst.yaml

@@ -8,6 +8,7 @@ rules:
     correct_code_block_directive_based_on_the_content: ~
     deprecated_directive_should_have_version: ~
     ensure_exactly_one_space_between_link_definition_and_link: ~
+    ensure_link_definition_contains_valid_url: ~
     ensure_order_of_code_blocks_in_configuration_block: ~
     extend_abstract_controller: ~
     extension_xlf_instead_of_xliff: ~