fix: add windows specific ssh-config

[Bexanderthebex]

This attempts to fix https://github.com/cloudflare/cloudflared/issues/753

The bug occurs because windows executable uses the current working directory to do its operations while the ssh-config being generated assumes that:

1. the user uses a nix machine
2. the nix executable follows a different installation directory than windows. Windows uses the relative path, the nix binary gets stored in ~/.cloudflared

[Bexanderthebex]

@GreenStage thank you for taking a look. I did the changes on my windows partition and forget about the spacing (I don't use it a lot) so thank you for noticing that.

[Bexanderthebex]

@jroyal wonder if you can take a look?

[GreenStage]

Generated

Host cfpipe-ssh.hotdogs.beauty
  ProxyCommand C:\Users\EduardoGomes\cloudflared\cloudflared.exe access ssh-gen --hostname %h && ssh -tt %[email protected] >&2 <&1

Host cfpipe-ssh.hotdogs.beauty
  HostName ssh.hotdogs.beauty
  ProxyCommand C:\Users\EduardoGomes\cloudflared\cloudflared.exe access ssh --hostname %h IdentityFile <REDACTED>
  CertificateFile <REDACTED>

after which, I got timedout when sshing to my remote machine

C:\Users\EduardoGomes>ssh -v ssh.hotdogs.beauty
OpenSSH_for_Windows_8.1p1, LibreSSL 3.0.2
debug1: Reading configuration data C:\\Users\\EduardoGomes/.ssh/config
debug1: Connecting to ssh.hotdogs.beauty [172.67.201.145] port 22.
debug1: connect to address 104.21.52.171 port 22: Connection timed out

[chungthuang]

Feel free to rebase and reopen it if it's still relevant.