feat: add leptos_animate crate

.cargo/config.toml

@@ -1,2 +1,8 @@
 [target.'cfg(target_os = "linux")']
-rustflags = ["-C", "link-arg=-fuse-ld=mold"]
+rustflags = [
+    "--cfg=web_sys_unstable_apis",
+    "-C", "link-arg=-fuse-ld=mold"
+]
+
+[target.wasm32-unknown-unknown]
+rustflags = ["--cfg=web_sys_unstable_apis"]