make groups sentence case

Author: ethanpalm

docs.json

@@ -19,7 +19,7 @@
         "description": "Set up your documentation",
         "groups": [
           {
-            "group": "Getting Started",
+            "group": "Getting started",
             "pages": [
               "index",
               "quickstart",
@@ -28,7 +28,7 @@
             ]
           },
           {
-            "group": "Core Configuration",
+            "group": "Core configuration",
             "pages": [
               "settings",
               "pages",
@@ -65,7 +65,7 @@
             ]
           },
           {
-            "group": "API Pages",
+            "group": "API pages",
             "pages": [
               "api-playground/overview",
               "api-playground/openapi-setup",
@@ -99,7 +99,7 @@
             ]
           },
           { 
-            "group": "Authentication and Personalization",
+            "group": "Authentication and personalization",
             "pages": [
               "authentication-personalization/overview",
               "authentication-personalization/authentication-setup",
@@ -197,7 +197,7 @@
             ]
           },
           {
-            "group": "Version Control and CI/CD",
+            "group": "Version control and CI/CD",
             "pages": [
             "settings/github",
               "settings/gitlab",