Move best solutions docs / best practices to engine development since it's focused on that. Use the 'ideas' section from FAQ for the ideas article.

engine/guidelines/best_practices.rst

@@ -1,7 +1,7 @@
 .. _doc_best_practices_for_engine_contributors:
 
-Proposal guidelines
-===================
+Best practices for engine contributors
+======================================
 
 Introduction
 ------------

engine/guidelines/index.rst

@@ -7,6 +7,7 @@ This section explains guidelines for contributing to the engine.
    :maxdepth: 1
    :name: sec-engine-contribution-guidelines
 
+   best_practices
    cpp_usage_guidelines
    code_style
 

index.rst

@@ -67,7 +67,7 @@ TODO
    :caption: Other
    :name: sec-other
 
-   other/ideas/index
+   other/ideas
    other/website
    other/demos
    other/benchmarks

other/ideas.rst

@@ -0,0 +1,27 @@
+Contributing ideas and change proposals
+=======================================
+
+We are always looking for suggestions about how to improve the engine. User feedback
+is the main driving force behind our decision-making process, and limitations that
+you might face while working on your project are a great data point for us when considering
+engine enhancements.
+
+If you experience a usability problem or are missing a feature in the current version of
+Godot, start by discussing it with our `community <https://godotengine.org/community/>`_.
+There may be other, perhaps better, ways to achieve the desired result that community members
+could suggest. And you can learn if other users experience the same issue, and figure out
+a good solution together.
+
+If you come up with a well-defined idea for the engine, feel free to open a
+`proposal issue <https://github.com/godotengine/godot-proposals/issues>`_.
+Try to be specific and concrete while describing your problem and your proposed
+solution — only actionable proposals can be considered. It is not required, but
+if you want to implement it yourself, that's always appreciated!
+
+If you only have a general idea without specific details, you can open a
+`proposal discussion <https://github.com/godotengine/godot-proposals/discussions>`_.
+These can be anything you want, and allow for a free-form discussion in search of
+a solution. Once you find one, a proposal issue can be opened.
+
+Please, read the `readme <https://github.com/godotengine/godot-proposals/blob/master/README.md>`_
+document before creating a proposal to learn more about the process.

other/ideas/index.rst

@@ -1,10 +0,0 @@
-Contributing ideas and change proposals
-=======================================
-
-TODO
-
-.. toctree::
-   :maxdepth: 1
-   :name: sec-contributing-ideas
-
-   guidelines