Add some basic docs to `Default_Temp_Allocator`

base/runtime/default_temporary_allocator.odin

@@ -4,6 +4,7 @@ DEFAULT_TEMP_ALLOCATOR_BACKING_SIZE: int : #config(DEFAULT_TEMP_ALLOCATOR_BACKIN
 NO_DEFAULT_TEMP_ALLOCATOR: bool : ODIN_OS == .Freestanding || ODIN_DEFAULT_TO_NIL_ALLOCATOR
 
 when NO_DEFAULT_TEMP_ALLOCATOR {
+	// `Default_Temp_Allocator` is a `nil_allocator` when `NO_DEFAULT_TEMP_ALLOCATOR` is `true`.
 	Default_Temp_Allocator :: struct {}
 	
 	default_temp_allocator_init :: proc(s: ^Default_Temp_Allocator, size: int, backing_allocator := context.allocator) {}
@@ -20,6 +21,11 @@ when NO_DEFAULT_TEMP_ALLOCATOR {
 	default_temp_allocator_temp_end :: proc(temp: Arena_Temp, loc := #caller_location) {
 	}
 } else {
+	// `Default_Temp_Allocator` is an `Arena` based type of allocator. See `runtime.Arena` for its implementation.
+	// The default `context.temp_allocator` is typically called with `free_all(context.temp_allocator)` once per "frame-loop"
+	// to prevent it from "leaking" memory.
+	//
+	// Note: `Default_Temp_Allocator` is a `nil_allocator` when `NO_DEFAULT_TEMP_ALLOCATOR` is `true`.
 	Default_Temp_Allocator :: struct {
 		arena: Arena,
 	}