Docs: Fix theme.mode default settings (#14153)

Peter Tripp created

- Updated docs to match the changes made in
https://github.com/zed-industries/zed/pull/13621
- Fixes: #14084.

Change summary

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

Detailed changes

docs/src/configuring-zed.md 🔗

@@ -1454,7 +1454,7 @@ At the moment, only the `title` option is available, it controls displaying of t
 
 ```json
 "theme": {
-  "mode": "dark",
+  "mode": "system",
   "dark": "One Dark",
   "light": "One Light"
 },
@@ -1464,7 +1464,7 @@ At the moment, only the `title` option is available, it controls displaying of t
 
 - Description: Specify theme mode.
 - Setting: `mode`
-- Default: `dark`
+- Default: `system`
 
 **Options**