Increase recursion limit

Changes[1] to the Rust standard library are affecting[2] the nesting
size of types to the point where typed-html can not be built on nightly.

This resolves the issue by increasing the acceptable recursion depth for
the crate.

[1]: rust-lang/rust#70896
[2]: rust-lang/rust#71359

Closes: bodil#112

typed-html/src/lib.rs

@@ -1,4 +1,4 @@
-#![recursion_limit = "128"]
+#![recursion_limit = "256"]
 //! This crate provides the `html!` macro for building HTML documents inside your
 //! Rust code using roughly [JSX] compatible syntax.
 //!