Implement the runtime metadata file (toml)

[Angelmmiguel]

These kind of files will be managed by wws, so it requires a representation in the source code. For consistency with the project, we chose the format as TOML.

The purpose of them is to "teach" wws how to use certain runtime and which files can be run with it. For this reason, it must include information about the name, version and binary, but also polyfills, arguments and environment variables.

Content

Property	Type	Description
name	String	The runtime name
version	String	The runtime version number
tags	String[]	Version aliases to simplify installation
status	Enum	The status of the given runtime: active, yanked, deprecated
binary	RemoteFile	A remote file that points to the runtime binary
extensions	String[]	Associated file extensions to this runtime
polyfill (optional)	RemoteFile	An associated source file with polyfills. It will be mounted inside lib folder using WASI
wrapper (optional)	RemoteFile	An optional wrapper file in case the source code needs to be modified. For example, to load a library or to add a function call. The provided code will be available in the {code} key
template (optional)	RemoteFile	An optional file to bootstrap new workers from the wws CLI.
args	String[]	Arguments to pass in the WASI context
envs (optional)	HashMap<String, String>	Default environment variables

Still under discussion

Property	Type	Description
folders (optional)	HashMap<String, Object>	A list of folders to mount with this runtime. It includes URL to download a compressed file, mount point and if decompression is required.

We may change these names or add some of them in the future.