Document coding standards (#779)

Adds documentation explaining the coding standards to follow.

Co-authored-by: F1F7Y <64418963+F1F7Y@users.noreply.github.com>

README.md

@@ -9,4 +9,6 @@ Check [BUILD.md](BUILD.md) for instructions on how to compile, you can also down
 
 ## Format
 
+For project coding standards check out [STANDARDS.md](STANDARDS.md).
+
 This project uses [clang-format](https://clang.llvm.org/docs/ClangFormat.html), make sure you run `clang-format -i --style=file --exclude=primedev/include primedev/*.cpp primedev/*.h` when opening a Pull Request. Check the tool's website for instructions on how to integrate it with your IDE.

STANDARDS.md

@@ -0,0 +1,53 @@
+# Code standards
+
+There are exceptions, ask for them!
+
+### Preamble
+
+You are more than welcome to reformat any existing files using these rules should they fail to match them but please SPLIT your formatting changes from the rest by making a separate PR!
+
+### General rules
+
+> Basic rules that apply all the time.
+
+Always assert your assumptions!
+
+Use PascalCase for all names.
+
+Suffix structs with `_t`.
+
+Prefix classes with `C` (class) and `I` (abstract class).
+
+Prefix all class member variables with `m_`.
+
+Prefixes `g_` for global variables and `s_` for static variables are welcome.
+
+For hooking we use `o_<function name>` for function pointers pointing to the original implementation and `h_<function name>` for functions we replace them with.
+
+Document all function implementations and their arguments (if the argument is self explanatory you don't need to document it) valve style:
+```
+//-----------------------------------------------------------------------------
+// Purpose: MH_MakeHook wrapper
+// Input  : *ppOriginal - Original function being detoured
+//          pDetour - Detour function
+// Output : true on success, false otherwise
+//-----------------------------------------------------------------------------
+```
+
+Don't overcomment your code unless nescessary, expect the reader to have limited knowledge.
+
+Use `FIXME` comments for possible improvements/issues, `NOTE` for important information one might want to look into.
+
+### Valve source files
+
+> Rules that apply to all files from original valve code base.
+
+When adding or just modifying a file that's present in valve source place it where valve put it.
+
+Always use hungarian notation in these files.
+
+### New files
+
+> Rules that apply to Respawn or our own files.
+
+When adding new files follow the general rules, you don't have to use hungarian notation. Put the file where you think it makes the most sense.