Allow onboarding pages to be zoomed in/out (#43244)

We were just missing adding keybindings for these.

Release Notes:

- onboarding: The onboarding pages can now be zoomed in/out with the
same keybindings you'd use to zoom in/out a regular buffer.

Author: danilo-leal

assets/keymaps/default-linux.json

@@ -1251,11 +1251,25 @@
     "context": "Onboarding",
     "use_key_equivalents": true,
     "bindings": {
+      "ctrl-=": ["zed::IncreaseUiFontSize", { "persist": false }],
+      "ctrl-+": ["zed::IncreaseUiFontSize", { "persist": false }],
+      "ctrl--": ["zed::DecreaseUiFontSize", { "persist": false }],
+      "ctrl-0": ["zed::ResetUiFontSize", { "persist": false }],
       "ctrl-enter": "onboarding::Finish",
       "alt-shift-l": "onboarding::SignIn",
       "alt-shift-a": "onboarding::OpenAccount"
     }
   },
+  {
+    "context": "Welcome",
+    "use_key_equivalents": true,
+    "bindings": {
+      "ctrl-=": ["zed::IncreaseUiFontSize", { "persist": false }],
+      "ctrl-+": ["zed::IncreaseUiFontSize", { "persist": false }],
+      "ctrl--": ["zed::DecreaseUiFontSize", { "persist": false }],
+      "ctrl-0": ["zed::ResetUiFontSize", { "persist": false }]
+    }
+  },
   {
     "context": "InvalidBuffer",
     "use_key_equivalents": true,

assets/keymaps/default-macos.json

@@ -1356,11 +1356,25 @@
     "context": "Onboarding",
     "use_key_equivalents": true,
     "bindings": {
+      "cmd-=": ["zed::IncreaseUiFontSize", { "persist": false }],
+      "cmd-+": ["zed::IncreaseUiFontSize", { "persist": false }],
+      "cmd--": ["zed::DecreaseUiFontSize", { "persist": false }],
+      "cmd-0": ["zed::ResetUiFontSize", { "persist": false }],
       "cmd-enter": "onboarding::Finish",
       "alt-tab": "onboarding::SignIn",
       "alt-shift-a": "onboarding::OpenAccount"
     }
   },
+  {
+    "context": "Welcome",
+    "use_key_equivalents": true,
+    "bindings": {
+      "cmd-=": ["zed::IncreaseUiFontSize", { "persist": false }],
+      "cmd-+": ["zed::IncreaseUiFontSize", { "persist": false }],
+      "cmd--": ["zed::DecreaseUiFontSize", { "persist": false }],
+      "cmd-0": ["zed::ResetUiFontSize", { "persist": false }]
+    }
+  },
   {
     "context": "InvalidBuffer",
     "use_key_equivalents": true,

assets/keymaps/default-windows.json

@@ -1285,11 +1285,25 @@
     "context": "Onboarding",
     "use_key_equivalents": true,
     "bindings": {
+      "ctrl-=": ["zed::IncreaseUiFontSize", { "persist": false }],
+      "ctrl-+": ["zed::IncreaseUiFontSize", { "persist": false }],
+      "ctrl--": ["zed::DecreaseUiFontSize", { "persist": false }],
+      "ctrl-0": ["zed::ResetUiFontSize", { "persist": false }],
       "ctrl-enter": "onboarding::Finish",
       "alt-shift-l": "onboarding::SignIn",
       "shift-alt-a": "onboarding::OpenAccount"
     }
   },
+  {
+    "context": "Welcome",
+    "use_key_equivalents": true,
+    "bindings": {
+      "ctrl-=": ["zed::IncreaseUiFontSize", { "persist": false }],
+      "ctrl-+": ["zed::IncreaseUiFontSize", { "persist": false }],
+      "ctrl--": ["zed::DecreaseUiFontSize", { "persist": false }],
+      "ctrl-0": ["zed::ResetUiFontSize", { "persist": false }]
+    }
+  },
   {
     "context": "GitWorktreeSelector || (GitWorktreeSelector > Picker > Editor)",
     "use_key_equivalents": true,