Bezier-rs: Add joins and caps to offsets and outlines (#1083)

* Intial work

* Improve miter and add round join

* Get arcs to go opposite direction

* Add cap and other refactors

* Rename joint to join, fix some bugs

* Fix single point issue

* Clean up

* Fix iframe sizes and update UI

* Address comments and handle single point outline

* Rename variables, fix branches in outline

* Address comments

website/other/bezier-rs-demos/wasm/src/utils.rs

@@ -0,0 +1,19 @@
+use bezier_rs::{Cap, Join};
+
+pub fn parse_join(join: i32) -> Join {
+	match join {
+		0 => Join::Bevel,
+		1 => Join::Miter,
+		2 => Join::Round,
+		_ => panic!("Unexpected Join value: '{}'", join),
+	}
+}
+
+pub fn parse_cap(cap: i32) -> Cap {
+	match cap {
+		0 => Cap::Butt,
+		1 => Cap::Round,
+		2 => Cap::Square,
+		_ => panic!("Unexpected Cap value: '{}'", cap),
+	}
+}