build target documentation missing no-modules

[petr-tik]

Documentation of wasm-pack build doesn't show one of the available target options for wasm-bindgen.

🐛 Bug description

The wasm-pack build command takes a target argument. According to the help message:

wasm-pack build -h | rg target`
    -t, --target <target>      Sets the target environment. [possible values: browser, nodejs] [default: browser]

Only 2 values are possible - browser or nodejs.

🤔 Expected Behavior

The source code in the src/bindgen.rs passes the --target flag to wasm-bindgen, which also takes a third value - no-modules to build a wasm library that can be shipped without webpack

https://github.com/rustwasm/wasm-pack/blob/master/src/bindgen.rs#L175-L178

Running

$$$$ wasm-pack build -t no-modules 

works as expected, so we should add a line to the documentation or even generate documentation automatically.

🌍 Your environment

Include the relevant details of your environment.
wasm-pack version: wasm-pack-build 0.5.1
rustc version: rustc 1.31.0-nightly (3e6f30ec3 2018-10-26)

This will help

Other non-web developers, who don't know how to set up webpack and prefer to build wasm to small JS bundles that they can ship manually.

rustwasm/wasm-bindgen#1034 (comment)

[petr-tik]

People developing this - thank you for your good work. It's a duplicate - closing.

Opened an issue, forked the repo, so I can open a quick PR, found that the issue below raised it and it has been fixed
#416

Looking forward to the next release.