Restructure project directories (#333)

`/client/web` -> `/frontend`
`/client/cli` -> *delete for now*
`/client/native` -> *delete for now*
`/core/editor` -> `/editor`
`/core/document` -> `/graphene`
`/core/renderer` -> `/charcoal`
`/core/proc-macro` -> `/proc-macros` *(now plural)*

editor/src/tool/tool_options.rs

@@ -0,0 +1,23 @@
+use serde::{Deserialize, Serialize};
+
+// TODO: Rename this `ToolOption` to not be plural in a separate commit (together with `enum LayerDataTypes`)
+#[derive(Debug, Clone, Copy, Eq, PartialEq, Serialize, Deserialize, Hash)]
+pub enum ToolOptions {
+	Select { append_mode: SelectAppendMode },
+	Ellipse,
+	Shape { shape_type: ShapeType },
+}
+
+#[derive(Debug, Clone, Copy, Eq, PartialEq, Serialize, Deserialize, Hash)]
+pub enum SelectAppendMode {
+	New,
+	Add,
+	Subtract,
+	Intersect,
+}
+
+#[derive(Debug, Clone, Copy, Eq, PartialEq, Serialize, Deserialize, Hash)]
+pub enum ShapeType {
+	Star { vertices: u32 },
+	Polygon { vertices: u32 },
+}