Re-link the proposal system internally and fix another.

Author: Ivorforce

documentation/contributing_to_the_contributing_docs.rst

@@ -12,7 +12,7 @@ involvement is just as welcome on this site as in the rest of Godot's
 documentation!
 
 If you'd like to submit an idea for a change of guidelines or operations,
-please consider proposing it as an :ref:`idea <_doc_contributing_ideas>`
+please consider proposing it as an :ref:`idea <doc_contributing_ideas>`
 instead of attempting to change the docs directly.
 
 Making changes to the contributing docs

engine/introduction.rst

@@ -54,7 +54,7 @@ way more contributions than people validating them.
 
 To make sure that your time and efforts aren't wasted, it is recommended to vet the idea
 first before implementing it and putting it for a review as a PR. To that end, Godot
-has a `proposal system <https://github.com/godotengine/godot-proposals>`_. Its
+has a :ref:`proposal system <doc_contributing_ideas>`. Its
 usage is encouraged to plan changes and discuss them with the community. Implementation
 details can also be discussed with other contributors on the `Godot Contributors Chat <https://chat.godotengine.org/>`_.