dev-desktop: Git email config docs doesn't match implementation

[aDotInTheVoid]

The dev-desktop docs say you should check that your email has been setup before running init.sh

rust-forge/src/infra/docs/dev-desktop.md

Lines 54 to 81 in 7932498

	## How to set up your account
	When connecting to the machine for the first time, there are a few things you
	might want to do.
	First, check that your Git username and email are configured correctly.
	```shell
	git config -l --global
	```
	You can configure your username and email address with:
	```shell
	git config --global user.name "Your name"
	git config --global user.email "your-email"
	```
	## How to install a Rust toolchain
	The dev desktops don’t have Rust pre-installed, but instead make it easy to
	install a specific toolchain from a local repository or worktree.
	First, you want to run the following command to install `rustup`:
	```shell
	/usr/local/bin/init.sh
	```

However running init.sh is what sets up a users git to have their name and email (from rust-lang/team)

https://github.com/rust-lang/simpleinfra/blob/f913b2b4d76b327031c3be225d54dc7e8a940241/ansible/roles/dev-desktop/files/scripts/init.sh#L8

We should change the docs to first have user's run init.sh, and then check that their gitconfig is correct.