Documentation: Clarify shortcuts and fix grammar (#6821)

Kieran Gill and Marshall Bowers created 

I got stuck on the "Getting started" page because I was trying to use
the shortcut `⌘+,` and not `⌘,`. This PR removes the `+`'s to make the
shortcuts clearer to the reader.

Release Notes:

- Improved getting started instructions.

---------

Co-authored-by: Marshall Bowers <elliott.codes@gmail.com>

Change summary

docs/src/getting_started.md | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

Detailed changes

docs/src/getting_started.md 🔗 

@@ -8,8 +8,8 @@ You can obtain the release build via the [download page](https://zed.dev/downloa
 
 ### Configure Zed
 
-Use `CMD + ,` to open your custom settings to set things like fonts, formatting settings, per-language settings and more. You can access the default configuration using the `Zed > Settings > Open Default Settings` menu item. See Configuring Zed for all available settings.
+Use `⌘` + `,` to open your custom settings to set things like fonts, formatting settings, per-language settings and more. You can access the default configuration using the `Zed > Settings > Open Default Settings` menu item. See Configuring Zed for all available settings.
 
 ### Set up your key bindings
 
-You can access the default key binding set using the `Zed > Settings > Open Default Key Bindings` menu item. Use `CMD + K`,`CMD + S` to open your custom keymap to add your own key bindings. See Key Bindings for more info.,
+You can access the default key binding set using the `Zed > Settings > Open Default Key Bindings` menu item. Use `⌘` + `K`, `⌘` + `S` to open your custom keymap to add your own key bindings. See Key Bindings for more info.