x/playground: consider alternative keyboard shortcut for "Run this code"

[Deleplace]

What version of Go are you using (go version)?

go1.20.1

(in the playground actually, not my computer)

Popular playgrounds' key bindings for "Run"

Playground		macOS	Linux	Windows
Go	https://go.dev/play/	Shift-Enter	Shift-Enter	Shift-Enter
Rust	https://play.rust-lang.org/	Cmd-Enter OR Ctrl-Enter	Ctrl-Enter	Ctrl-Enter
Dart	https://dartpad.dev/	Cmd-Enter OR Ctrl-Enter	Ctrl-Enter	Ctrl-Enter
Kotlin	https://play.kotlinlang.org/	Ctrl-R	Ctrl-F9	Ctrl-F9
Sharplab	https://sharplab.io/	autoplay	autoplay	autoplay
Wandbox	https://wandbox.org/	Ctrl-Enter	Ctrl-Enter	Ctrl-Enter
Colab	https://colab.google/	Cmd-Enter OR Ctrl-Enter	Ctrl-Enter	Ctrl-Enter
BigQuery	https://console.cloud.google.com/bigquery	Cmd-Enter	Ctrl-Enter	Ctrl-Enter

In general

It would be nice to reach convergence among different playgrounds for this specific standard feature, for the same reasons that it's nice to have (often) the same shortcut for Copy & Paste

Suggestion for Go's playground

Add Ctrl-Enter (Linux, Windows) / Cmd-Enter (macOS) as bindings for "Run this code".

This seems to be more widespread and more intuitive than the current binding Shift-Enter.

This can be done while keeping the existing binding Shift-Enter.

This does conflict on Linux with the current binding for "Format this code", so we'd need to decide if changing things for "Format this code" is acceptable damage.

[cagedmantis]

/cc @toothrot @findleyr