Auto merge of #6881 - k-nasa:feature_cargo_toml_template, r=alexcrichton
Default Cargo.toml template provide help for completing the metadata
## Descriptio
This is new Cargo.toml example.
```toml
[package]
name = "foo"
version = "0.1.0"
authors = ["k-nasa"]
documentation = ""
homepage = ""
repository = ""
readme = ""
categories = []
keywords = []
license = ""
edition = "2018"
[dependencies]
# See more https://doc.rust-lang.org/cargo/reference/manifest.html
```
## Motivation
close: https://github.com/rust-lang/cargo/issues/6845