Remove outdated comment about path dependency.

[mstange]

The "Hello, World!" chapter of the wasm-bindgen Guide contains an sentence about a path dependency in the Cargo.toml section: https://rustwasm.github.io/docs/wasm-bindgen/examples/hello-world.html

The Cargo.toml enables depends on the wasm-bindgen crate. Here we're using a path dependency because this example lives in the wasm-bindgen repository itself, but you'd use the commented out version beneath it instead.

But then the quoted code section shows a regular version dependency:

[dependencies]
wasm-bindgen = "0.2.62"

The path dependency was turned into a regular version dependency in PR #1015.

This PR also changes the phrasing in the preceding sentence, to eliminate the odd "enables depends" fragment.

[alexcrichton]

Thanks!