Add start of spec

spec.md

@@ -0,0 +1,77 @@
+# Spec for ByteCode
+
+:: All value starting with `0x` are hexadecimal
+
+|-----------------------------------------------------------------------------|
+| Header                                                                      |
+|-----------------------------------------------------------------------------|
+| Struct registration                                                         |
+|-----------------------------------------------------------------------------|
+| Global variable registration                                                |
+|-----------------------------------------------------------------------------|
+| Function registration                                                       |
+|-----------------------------------------------------------------------------|
+| Start function                                                              |
+|-----------------------------------------------------------------------------|
+
+## Header
+
+1. The file starts with:
+
+```
+0x55 0x1E 0x53 0x0A
+```
+
+## Struct registration
+
+|-----------------------------------------------------------------------------|
+| 0x01 0xZZZZZZZZ 0x                                                         |
+|-----------------------------------------------------------------------------|
+
+Struct ID for:
+- __Int__: `0x00000001`
+- __String__: `0x00000002`
+- __Bool__: `0x00000003`
+- __Void__: `0x00000004`
+- __Char__: `0x00000005`
+
+1. The section starts with:
+
+```
+0x00 0x06 0x07 0x00
+```
+
+
+
+2. Struct are a list of other struct of built-in types
+
+- Struct start
+
+```
+0x01
+```
+
+- Struct name (Int32) is an `ID` of the struct name.
+
+All reference to this struct will be with the `ID`.
+
+- Number of fields (Int16)
+
+- Each fild is a `ID` of the field type
+
+- Struct end
+
+```
+0x00
+```
+
+
+```
+struct a {
+    int
+}
+
+struct b {
+    a
+}
+```