Improve readme

README.md

@@ -2,27 +2,57 @@
 
 [![Build Status](https://dev.azure.com/samueltebbs/pluto/_apis/build/status/SamTebbs33.pluto?branchName=develop)](https://dev.azure.com/samueltebbs/samueltebbs/_build/latest?definitionId=1&branchName=develop)
 
+Pluto is a kernel written almost entirely in [Zig](https://github.com/ziglang/zig) and supports x86, with aarch64 and x64 backends being planned.
+
+![Hello image](hello.jpg)
+
+## Goals
+* **Should be written in Zig as much as possible**. Assembly should only be used where required for functionality or performance reasons.
+* **Light and performant**. The kernel should be usable both on embedded and desktop class CPUs, made possible by it being lightweight and modular.
+* **Basic utilities will be written in Zig**. This includes a basic text editor and shell, and will be part of the filsystem external to the kernel itself.
+* **Easy to port**. The kernel is oblivous to the underlying architecture, meaning that ports only need to implement the defined interface and they should work without a hitch.
+
+All of these goals will benefit from the features of Zig.
+
 ## Build
-Requires *xorriso* and the grub tools (such as *grub-mkrescue*).
+Requires a master build of Zig ([downloaded](https://ziglang.org/download) or [built from source](https://github.com/ziglang/zig#building-from-source)) *xorriso* and the grub tools (such as *grub-mkrescue*). A gdb binary compatible with your chosen target is required to run the kernel (e.g. *qemu-system-i386*).
 ```
-mkdir -p bin/kernel
-mkdir -p bin/iso/boot/grub
 zig build
 ```
 
-Note that the `mkdir` invocations are only needed once. See `zig build --help` for a list of options.
-
 ## Run
 ```
 zig build run
 ```
-To debug the kernel:
+
+## Debug
+Launch a gdb instance and connect to qemu.
 ```
-zig build run -Ddebug=true
 zig build debug
 ```
 
-# Test
+## Test
+Run the unitests or runtime tests.
 ```
 zig build test
 ```
+
+## Options
+* `-Ddebug=`: Boolean (default `false`).
+	* **build**: Build with debug info included or stripped (see #70 for planned changes).
+	* **run**: Wait for a gdb connection before executing.
+* `-Drt-test=`: Boolean (default `false`).
+	* **build**: Build with runtime testing enabled. Makes the kernel bigger and slower but tests important functionality.
+	* **test**: Run the runtime testing script instead of the unittests. Checks for the expected log statements and fails if any are missing.
+
+## Contribution
+We welcome all contributions, be it bug reports, feature suggestions or pull requests. We follow the style mandated by zig fmt so make sure you've run `zig fmt` on your code before submitting it.
+
+We also like to order a file's members (public after non-public):
+1. imports
+2. type definitions
+3. constants
+4. variables
+5. inline functions
+6. functions
+7. entry point/init function