[docs] Tighten AI restrictions and switch to CONTRIBUTING.md (#4193)

Also removes some now-unnecessary docs files.

Signed-off-by: crueter <crueter@eden-emu.dev>
Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/4193
Reviewed-by: MaranBr <maranbr@eden-emu.dev>
Reviewed-by: Lizzie <lizzie@eden-emu.dev>

docs/policies/Coding.md

@@ -2,44 +2,41 @@
 
 These are **not** stylistic guidelines, they're, for the most part, suggestions on how to architecture new systems or improve upon the existing codebase.
 
-# Foreword
+## Foreword
 
-Don't try to micro-optimize out of the get go, while yes, most of the code is pretty, subpar, most of these are aftertoughts and details that can be glossed over **generally**.
+Keep your code simple, efficient, and readable.
 
-Architectural issues are more important, for example an API returning a `std::string` is not as efficient as one that operates on `std::string_view` directly (cost of constructing an `std::string` w/o small-string optimization and all of that).
-
-Regardless of the details, try to keep things simple. As a general rule of thumb.
-
-# C++ guidelines
+## C++ guidelines
 
 Everyone has their own way of viewing good/bad C++ practices, my general outline:
 
 - At your disposal you may use `boost::container::static_vector<>` (beware it has a ctor/initialization cost which goes up the more elements you add).
-    - Or you may use `boost::container::small_vector<>` (which has an initialization cost as well, and will use extra book-keeping for heap, try to keep a balance).
+  - Or you may use `boost::container::small_vector<>` (which has an initialization cost as well, and will use extra book-keeping for heap, try to keep a balance).
 - Don't use `[[likely]]` or `[[unlikely]]`; PGO builds exist for that.
 - Don't use inline assembly to try to outsmart the compiler unless you're 100% sure the assembly you're writing is actually good.
-    - And if so, try to restructure your C++ code so the compiler vectorizes it/makes it better, right?
-    - Or if that fails, use intrinsics instead of raw `asm volatile`.
+  - And if so, try to restructure your C++ code so the compiler vectorizes it/makes it better
+  - Or if that fails, use intrinsics instead of raw `asm volatile`.
 - Use `std::optional<>` instead of `std::unique_ptr<>` if possible.
-    - `std::unique_ptr<>` carries indirection cost due to it being memory allocated on the heap.
-    - It isn't often that objects that contain `std::unique_ptr<>`, are allocated on the heap themselves, allocating even more things on the heap seems redundant.
+  - `std::unique_ptr<>` carries indirection cost due to it being memory allocated on the heap.
+  - It isn't often that objects that contain `std::unique_ptr<>`, are allocated on the heap themselves, allocating even more things on the heap seems redundant.
 - Avoid `std::recursive_mutex` at all costs.
-    - It's basically implemented as a linked list most of the time and has HEAVY performance penalties.
+  - It's basically implemented as a linked list most of the time and has HEAVY performance penalties.
 - Exploit the fact `std::atomic<uint32_t>/std::atomic<int32_t>` is basically free on most arches that matter.
-    - In x86_64, an atomic `uint32_t` is basically `mov [m32], r32`, which is essentially free/cheap.
+  - In x86_64, an atomic `uint32_t` is basically `mov [m32], r32`, which is essentially free/cheap.
 - Avoid template parameters unless you really need them.
-    - For small inlineable functions this is fine, for more complex ones, please consider the generated assembly.
+  - For small inlineable functions this is fine, for more complex ones, please consider the generated assembly.
 - Dont make your own memcpy/memset/strcpy/strncpy/etc.
-    - Seriously DON'T DO THIS. You will NOT beat the compiler.
-    - Nor 30 years of writing optimized `mem*`.
-    - If your code is slow, don't blame `mem*`, blame your code.
+  - Seriously DON'T DO THIS. You will NOT beat the compiler.
+  - Nor 30 years of writing optimized `mem*`.
+  - If your code is slow, don't blame `mem*`, blame your code.
 - Try to avoid using `virtual` since vtable indirection has a cost
 - Avoid `dynamic_cast` and `typeid` at all costs.
-    - The reason is because the project has `-fno-rtti` disabled by default, due to the costs of dynamic polymorphism.
+  - The reason is because the project has `-fno-rtti` disabled by default, due to the costs of dynamic polymorphism.
 - Always copy-on-value for objects with `sizeof(void *) >= sizeof(T) * 2`, i.e objects sized as 2 pointers or less, for bigger objects you can use ref/pointer as usual.
 - Try using move semantics instead of references, whenever possible.
 - Remember function parameters are extremelly cheap as fuck, don't be afraid to place upto 8 parameters on a given function.
 - Don't save a reference in structures of a parent object, i.e:
+
     ```c++
     struct Child {
         Parent& parent;
@@ -48,7 +45,9 @@ Everyone has their own way of viewing good/bad C++ practices, my general outline
         }
     };
     ```
-    - Instead you can do the following:
+
+  - Instead you can do the following:
+
     ```c++
     struct Child {
         void Mehod(Parent& parent) {
@@ -56,15 +55,17 @@ Everyone has their own way of viewing good/bad C++ practices, my general outline
         }
     };
     ```
-    - This reduces the amount of pointers you have lying around, and also works better because of the aforementioned cheapness of parameter functions.
 
-# Engineering guidelines
+  - This reduces the amount of pointers you have lying around, and also works better because of the aforementioned cheapness of parameter functions.
 
-Coding isn't also writing stuff but architecturing stuff, consider the following:
+## Engineering guidelines
 
-- Try to reduce dependency on... dependencies
-    - While some dependencies are useful `boost::container` and `fmt` to name a few, remember each dependency added incurs a cost.
-    - It may also be subpar with a hand rolled implementation, biggest exemplar of this is `spirv-tools` providing subpar SPIRV optimizations in comparison to the in-house optimizer.
+Programming, alongside the physical act of writing code, also consists of architecting the code you write into a coherent, maintainable system.
+
+- Try to reduce your usage of dependencies
+  - Dependencies that are legitimately useful to have are few and far between.
+  - At the same time, NIHing your own implementations of widely adopted algorithms or standards can be quite subpar.
+  - For dependencies that are very large but contain something you need, consider cherry-picking the individual files it needs (or writing a smaller version of it)
 - Try to rely less on indirection for architecturing systems
-    - If the underlying HLE kernel emulation requires it, try making a solution that keeps things local
-        - For example, there isn't a need for file descriptors to each be a pointer, when they could be a fixed table size with elements that may be emplaced at will.
+  - If the underlying HLE kernel emulation requires it, try making a solution that keeps things local
+    - For example, there isn't a need for file descriptors to each be a pointer, when they could be a fixed table size with elements that may be emplaced at will.