Add documentation for configuring editors for MsQuic dev (#2181)

* Add documentation for configuring editors for MsQuic dev

I get asked these questions a lot, so figure documenting how to get intellisense in VS Code warning free is worth it

* Smore cleanup

Author: thhous-msft

docs/Development.md

@@ -0,0 +1,110 @@
+# Developing MsQuic
+
+This document contains tips and tricks for configuring known editors to make MsQuic development easier.
+
+## Configuring Visual Studio Code for MsQuic
+
+Using the VS Code C/C++ Tools extension (https://marketplace.visualstudio.com/items?itemName=ms-vscode.cpptools)
+getting intellisense working for MsQuic is easy, but requires a small amount of configuration. The configuration UI
+can be started by going to the command palette (View -> Command Palette) and running `C/C++: Edit Configurations (UI)`.
+This UI is a bit awkward to use, to set a field you have to click on another field. If you click out of the window it
+won't save.
+
+For User Mode (Windows, Linux or macOS), the following defines need to be added to the configuration.
+
+```
+"_DEBUG",
+"UNICODE",
+"_UNICODE",
+"QUIC_EVENTS_STUB",
+"QUIC_LOGS_STUB"
+```
+
+Additionally, `cStandard` and `cppStandard` need to be set to `c17` and `c++17` respectively.
+
+
+For Kernel Mode, create a new configuration with the `Add Configuration` button and call it Kernel.
+
+Add a Compiler argument `/kernel` to force kernel mode in the compiler.
+
+Add the following defines
+
+```
+_DEBUG
+UNICODE
+_UNICODE
+QUIC_EVENTS_STUB
+QUIC_LOGS_STUB
+_AMD64_
+_WIN32_WINNT=0x0A00
+```
+
+Set `cStandard` and `cppStandard` to `c17` and `c++17` respectively.
+
+Finally, you'll need to add the kernel mode header paths to `Include path`. On my system they're
+
+```
+C:\Program Files (x86)\Windows Kits\10\Include\10.0.22000.0\km
+C:\Program Files (x86)\Windows Kits\10\Include\wdf\kmdf\1.33
+```
+Depending on which WDK you have installed, the versions might change, but the relative folder paths should be similar.
+
+You will have to switch between configurations depending on if you want kernel mode or user mode context. To do this,
+while youre in a c or cpp file the status bar on the buttom right will have the configuration mode. For user it will
+be called `Win32` and for kernel it will be called `Kernel`. To switch contexts, click the text, and you'll get a drop
+down to select other configurations.
+
+
+
+In the end, your c_cpp_properties.json file (in the .vscode folder) should look similar to the following. Some paths might be different, but they're trivially fixable.
+
+```
+{
+    "configurations": [
+        {
+            "name": "Win32",
+            "includePath": [
+                "${workspaceFolder}/**"
+            ],
+            "defines": [
+                "_DEBUG",
+                "UNICODE",
+                "_UNICODE",
+                "QUIC_EVENTS_STUB",
+                "QUIC_LOGS_STUB"
+            ],
+            "windowsSdkVersion": "10.0.22000.0",
+            "cStandard": "c17",
+            "cppStandard": "c++17",
+            "intelliSenseMode": "windows-msvc-x64",
+            "compilerPath": "C:/Program Files/Microsoft Visual Studio/2022/Enterprise/VC/Tools/MSVC/14.30.30705/bin/Hostx64/x64/cl.exe"
+        },
+        {
+            "name": "Kernel",
+            "includePath": [
+                "C:\\Program Files (x86)\\Windows Kits\\10\\Include\\10.0.22000.0\\km",
+                "C:\\Program Files (x86)\\Windows Kits\\10\\Include\\wdf\\kmdf\\1.33",
+                "${workspaceFolder}/**"
+            ],
+            "defines": [
+                "_DEBUG",
+                "UNICODE",
+                "_UNICODE",
+                "QUIC_EVENTS_STUB",
+                "QUIC_LOGS_STUB",
+                "_AMD64_",
+                "_WIN32_WINNT=0x0A00"
+            ],
+            "compilerPath": "C:/Program Files/Microsoft Visual Studio/2022/Enterprise/VC/Tools/MSVC/14.30.30705/bin/Hostx64/x64/cl.exe",
+            "windowsSdkVersion": "10.0.22000.0",
+            "cStandard": "c17",
+            "cppStandard": "c++17",
+            "intelliSenseMode": "windows-msvc-x64",
+            "compilerArgs": [
+                "/kernel"
+            ]
+        }
+    ],
+    "version": 4
+}
+```