README.md for SSH (#20365)

* SSH README

* table of contents fix

* fix ambiguity

* removed some useless sections

* Update README.md

* fix line

* cleanup

* add link

* this is correct

* Add notice that key is only fetched once

* Update README.md

* end of sentence

* Even more

* Update tools/ssh/README.md

* move ssh above tools

* remove useless sections

* succint

* note

Co-authored-by: Adeeb Shihadeh <adeebshihadeh@gmail.com>

tools/README.md

@@ -1,6 +1,12 @@
 openpilot tools
 ============
 
+SSH
+============
+
+Connecting to your comma device using [SSH](ssh/README.md)
+
+
 System requirements
 ============
 
@@ -66,7 +72,6 @@ Review video and log data from routes and stream CAN messages to your device.
 Use a joystick to control your car.
 
 
-
 Welcomed contributions
 =============
 

tools/ssh/README.md

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+# SSH
+
+## Quick Start
+
+In order to SSH into your device, you'll need a GitHub account with SSH keys. See this [GitHub article](https://docs.github.com/en/github/authenticating-to-github/connecting-to-github-with-ssh) for getting your account setup with SSH keys.
+
+* Enable SSH in your device's settings
+* Enter your GitHub username in the device's settings
+* Connect to your device
+  * Username: `root`
+  * Port: `22` or `8022`
+
+Here's an example command for connecting to your device using its tethered connection:
+`ssh root@192.168.43.1`
+
+For doing development work on device, it's recommended to use [SSH agent forwarding](https://docs.github.com/en/developers/overview/using-ssh-agent-forwarding).
+
+## Notes
+
+The public keys are only fetched from your GitHub account once. In order to update your device's authorized keys, you'll need to re-enter your GitHub username.
+
+See the [community wiki](https://github.com/commaai/openpilot/wiki/SSH) for more detailed instructions and information.