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

[Alona Enraght-Moony]

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.