terminal: Add setting for scroll multiplier (#39463)

Closes #5130

Release Notes:

- Added setting option for scroll multiplier of the terminal

---------

Signed-off-by: Marco Mihai Condrache <52580954+marcocondrache@users.noreply.github.com>
Co-authored-by: MrSubidubi <finn@zed.dev>

docs/src/configuring-zed.md

@@ -3586,6 +3586,7 @@ List of `integer` column numbers
     "option_as_meta": false,
     "button": true,
     "shell": "system",
+    "scroll_multiplier": 3.0,
     "toolbar": {
       "breadcrumbs": false
     },
@@ -3998,6 +3999,26 @@ Disable with:
 }
 ```
 
+### Terminal: Scroll Multiplier
+
+- Description: The multiplier for scrolling speed in the terminal when using mouse wheel or trackpad.
+- Setting: `scroll_multiplier`
+- Default: `1.0`
+
+**Options**
+
+Positive floating point values. Values less than or equal to 0 will be clamped to a minimum of 0.01.
+
+**Example**
+
+```json
+{
+  "terminal": {
+    "scroll_multiplier": 5.0
+  }
+}
+```
+
 ## Terminal: Toolbar
 
 - Description: Whether or not to show various elements in the terminal toolbar.